[sage-devel] Re: IDE's; science/engineering
On 12 Ago, 09:49, Jason Grout wrote: > On 7/22/10 2:36 PM, Maurizio wrote: > > > > > > > I have a quick question that is related to engineering support (I was > > reading the document you posted on the wiki about sd24, and I see the > > roadmap is planning to address those issues for SAGE 7.0.. ouch!): I > > don't know exactly how this is achieved, but I can see that > > > sage: type(1) > > > > > this should come from the fact that the preparser replaces usual > > numbers with sage numerical types. > > Nonetheless, still we have: > > > sage: type([1,2,3]) > > > > > This means that list are not replaced by anything internal, even if > > they are collector of python objects which are still sage numbers. I > > wonder which is the policy of SAGE towards arrays and matrices. I > > think there is a good base in numpy and scipy, so I wonder if it would > > make sense to let the preparser transform any list of numbers into a > > numpy array. That would greatly improve user ergonomy in case of raw > > numbers manipulation. > > That could be a not-default option, that could be activated using a > > function like: > > > def numpy_mode(str): > > if str == 'on': > > from numpy import * > > "turn any list into a numpy array" > > elif str == 'off': > > "reverse behaviour" > > > [I'm just talking on top of my head] > > This will probably require lots of changes in the sage codebase, since I > think there are lots of places that an input is tested to see if it is a > list. > > % find . -name \*.py\* | xargs grep isinstance |grep list|wc -l > 545 > > > > > Another slightly related issue is: could we make > > plot(numpy.array([1,2,3,4])) behave like > > list_plot(numpy_array([1,2,3,4]))? The way it is now, it just doesn't > > work... > > +1 to plot interpreting numpy arrays. However, shouldn't it interpret > the numpy arrays like it interprets lists? Right now, plot([1,2,3]) > works and plots the constant functions 1, 2, and 3. > > Thanks, > > Jason What would you expect from such a plot([1,2,3])? Personally,a plot of a list of points. If the argument of plot is a list of constant values,can we imagine to change the behavior such to replicate that of list_plot? -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: Some feature requests on SAGE - Adding Engineering to the target audience
> * a function that plots the Bode diagram. Once it's possible to (1) > draw logarithmic axes, (2) align plots on a graphic array so that both > horizontal axes scales match perfectly, and maybe (3) select the > divisions on the axes (it would be nicer to have divisions each 15 or > 45 degrees than each 20 or 50), the construction of the bode() > function will be trivial. Hi cousteau, let me share my Bode plot function I have written by deeply inspiring to the link I previously pointed out. I hope that can help you. It takes advantage of matplotlib plotting capabilities, so it should meet your requirements now. Unfortunately, I wrote it long ago so it is very unoptimized, even though it produces an output plot that I like and I consider usable for my purposes. It may be optimized, but I never tried to understand where the bottlenecks are, or maybe moved to using numpy arrays, I don't know if it may be faster. Let me know if you want to improve it, we may have a fruitful discussion :) Maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org bode.sage Description: Binary data
[sage-devel] Re: Some feature requests on SAGE - Adding Engineering to the target audience
Sorry, I mistyped the last part, which I replicate here. I would add to this list a different notebook interface, something like a single file editor, plus an online console... something like Matlab's IDE :) I'm actually investigating how difficult it would be using codemirror plugin (already in SAGE); I don't know how to hook in a new window (from the browser) a SAGE console session which is attached to the session of the notebook. Can anyone help with this? Maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: Some feature requests on SAGE - Adding Engineering to the target audience
ram*meter/second^2.0 > sage: a.convert(units.mass.gram * m / s^2) > 9800.0*gram*meter/second^2.0 > > > 3. BODE DIAGRAMS > > I didn't find it easy to plot a Bode diagram of a function. The plot() > > function doesn't appear to have a "logarithmic" option, and it doesn't > > look easy to put 2 parallel plots on the same image, one on the upper > > half and another on the lower half. > > Solution: have a bode() function that does all the work (along with > > nyquist() and maybe root_locus()). Extending the options on the plot() > > function would also be nice (at least, add logarithmic_x and > > logarithmic_y options). > > Parallel plots? Do you mean like this: > > sage: graphics_array([plot(sin(x), 0, 3), plot(cos(x),0,3)],2,1) > > > 4. MATRIX INPUT > > SAGE lacks an easy way to enter matrices. The easiest one is to do > > something like "matrix([[1,2],[3,4]])", but that's uncomfortable, > > specially for people who are used to Matlab's (or Octave's) "[1 2; 3 > > 4]". > > Solution: My proposed syntax is "[[1,2],[3,4]]m", this is, a literal > > list followed by an "m", as an alias to "matrix([[1,2],[3,4]])". Same > > for "v" (vectors), "c" (complex numbers), maybe "q" (quaternions), > > "p" (polynomials)... > > I think this is pretty easy: > > sage: matrix(2, [1,2, 3,4]) > [1 2] > [3 4] > > I don't like your suggestion to introduce something that isn't valid > Python to enter matrices. > > > 5. MATRIX INDEXES > > I had written a long paragraph about how easy is to get slices of > > matrices on Matlab/Octave and how good it would be to implement > > something similar on SAGE with some examples, just to realize that it > > was already implemented. :( > > (some examples: mat[3], mat[1,2], mat[0:3], mat[[3,2,1,0]], mat[:, > > 0]...) > > Moreover, if you use numpy arrays you get extremely powerful and > efficient slicing into n-dimensional arrays. This is very useful, > e.g., when dealing with 3d scientific data. > > > > > 6. TRANSPOSE/CONJUGATE > > If I want to get the transposed of a matrix, I have to write > > "mat.transpose()", while on Matlab it's as easy as "mat' ". Same for > > conjugating complex numbers or transposing+conjugating complex > > matrices. > > Solution: The solutions are to have a .T (or .H, .C...) attribute, or > > to have a custom operator that conjugates and transposes, such as > > "*mat" or "+mat" (the latter might be easier to implement since > > there's already an unary "+" operator in Python that doesn't do > > anything useful). > > Why don't you do this: > > sage: T = lambda x: x.transpose() > sage: A = matrix(3, [1,2, 3,4, 5,6]); A > [1 2] > [3 4] > [5 6] > sage: T(A) > [1 3 5] > [2 4 6] > > > > > -- > > To post to this group, send an email to sage-devel@googlegroups.com > > To unsubscribe from this group, send an email to > > sage-devel+unsubscr...@googlegroups.com > > For more options, visit this group > > athttp://groups.google.com/group/sage-devel > > URL:http://www.sagemath.org > > -- > William Stein > Professor of Mathematics > University of Washingtonhttp://wstein.orgs list a different notebook > interface, something like a single file editor, plus an online console... > something like Matlab's IDE :) I'm actually investigating how difficult it > would be using codemirror plugin (already in SAGE); I don't know how to hook > in a new window (from the browser) a SAGE console session which is attached > to the session of the notebook. Can anyone help with this? Maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: Sage and Python(x,y)
May there be any "official" way to explain reciprocally and fix this? I don't see any reason for not doing some effort in the direction of cooperation, I don't think there's any problem among the user communities Maurizio On Jul 23, 7:05 am, Jason Grout wrote: > On 7/22/10 9:53 PM, Afif Elghraoui wrote: > > I just read on their website > > > dedicated to Sage for Windows: "[...] Provide an alternative to > > Enthought's EPD, Python(x,y), and ActiveState Python: 100% free and > > open source, unlike any of the above systems [...]"... I wonder why > > they are accusing Python(x,y) to not be 100% free and open source... > > very disapointing and how outrageous! > > After looking at their website, it does seem like Python(x,y) is 100% > free and open source. It seems like we should > changehttp://windows.sagemath.org/to reflect that. > > I would have hoped they would have contacted us several months ago to > correct this, rather than just rant against it. > > Jason -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: IDE's; science/engineering
Wow... I just noticed the same discussion going on in sage-notebook... I am not a member there so let me say here that I definitely vote for adding in the preparser an option to directly get numpy arrays in SAGE without typing np.array(). I think that may be the boost for starting considering numpy as another key component of SAGE, and I don't think it can go anyway in science without supporting and being supported by scipy/numpy: collaboration looks much more promising! Maurizio On Jul 22, 11:36 pm, Maurizio wrote: > I have a quick question that is related to engineering support (I was > reading the document you posted on the wiki about sd24, and I see the > roadmap is planning to address those issues for SAGE 7.0.. ouch!): I > don't know exactly how this is achieved, but I can see that > > sage: type(1) > > > this should come from the fact that the preparser replaces usual > numbers with sage numerical types. > Nonetheless, still we have: > > sage: type([1,2,3]) > > > This means that list are not replaced by anything internal, even if > they are collector of python objects which are still sage numbers. I > wonder which is the policy of SAGE towards arrays and matrices. I > think there is a good base in numpy and scipy, so I wonder if it would > make sense to let the preparser transform any list of numbers into a > numpy array. That would greatly improve user ergonomy in case of raw > numbers manipulation. > That could be a not-default option, that could be activated using a > function like: > > def numpy_mode(str): > if str == 'on': > from numpy import * > "turn any list into a numpy array" > elif str == 'off': > "reverse behaviour" > > [I'm just talking on top of my head] > > Another slightly related issue is: could we make > plot(numpy.array([1,2,3,4])) behave like > list_plot(numpy_array([1,2,3,4]))? The way it is now, it just doesn't > work... > > The reason I'm doing this is that I assume a big income of users when > the windows port is ready (soon) and maybe there are a lot of non- > mathematicians among them. > > Could it be that it make sense to create a wiki page with all the > desiderata about SAGE/engineering? Maybe that may help in the long > run, like the one I created for the physical units package! I can see > that other scientists are in this community, I'm wondering if they may > help, being even more experienced in contributing to SAGE. > > Cheers > > Maurizio > > On Jul 14, 1:57 am, William Stein wrote: > > > > > On Wed, Jul 14, 2010 at 1:42 AM, Maurizio > > wrote: > > > I just spend a couple of words about IDEs. I've personally spent a > > > decent amount of time on Spyder and Eric, and my impressions are: > > > - Eric is very well suited for general software development, it is not > > > completely polished, and it lacks (at least explicitly, I didn't get > > > those) useful features for scientific computing (which I'll later > > > mention) > > > - Spyder is theoretically exactly what I was looking for: it is a > > > pythonized version of the Matlab GUI, which I felt very comfortable to > > > use; nonetheless, the problems are there: > > > 1) I find it very slow (even if I may have problems with matplotblib, > > > my workstation is quad-core and generally fast), certainly slower than > > > Eric (I think both are written in Python) > > > 2) window management is awful: if you undock an internal subwindow, > > > you are forced to not move it again within the area of the main Spyder > > > window, otherwise it immediately redocks it > > > 3) integrated plot management looks pretty, but (it's entirely not > > > Spyder's fault) matplotlib just outputs pictures, so plot navigation > > > is still orders of magnitude less evolved than Matlab's (I know it may > > > sound silly, but is that so difficult to do something better??) > > > on the pros side I count: > > > 1) both internal and external console: the former one is useful to do > > > experiments within the script you are editing, the latter is better to > > > have a clean environment > > > 2) variables management and browsing > > > 3) enhanced editing (code completion, syntax highlighting, classes > > > identification and browsing) > > > Very interesting. > > > 1. How does the speed of the Sage notebook running locally on your > > computer compare to Spyder locally on your computer? > > > 2. Are the plotting issues you mention the result of Spyder emb
[sage-devel] Re: IDE's; science/engineering
I have a quick question that is related to engineering support (I was reading the document you posted on the wiki about sd24, and I see the roadmap is planning to address those issues for SAGE 7.0.. ouch!): I don't know exactly how this is achieved, but I can see that sage: type(1) this should come from the fact that the preparser replaces usual numbers with sage numerical types. Nonetheless, still we have: sage: type([1,2,3]) This means that list are not replaced by anything internal, even if they are collector of python objects which are still sage numbers. I wonder which is the policy of SAGE towards arrays and matrices. I think there is a good base in numpy and scipy, so I wonder if it would make sense to let the preparser transform any list of numbers into a numpy array. That would greatly improve user ergonomy in case of raw numbers manipulation. That could be a not-default option, that could be activated using a function like: def numpy_mode(str): if str == 'on': from numpy import * "turn any list into a numpy array" elif str == 'off': "reverse behaviour" [I'm just talking on top of my head] Another slightly related issue is: could we make plot(numpy.array([1,2,3,4])) behave like list_plot(numpy_array([1,2,3,4]))? The way it is now, it just doesn't work... The reason I'm doing this is that I assume a big income of users when the windows port is ready (soon) and maybe there are a lot of non- mathematicians among them. Could it be that it make sense to create a wiki page with all the desiderata about SAGE/engineering? Maybe that may help in the long run, like the one I created for the physical units package! I can see that other scientists are in this community, I'm wondering if they may help, being even more experienced in contributing to SAGE. Cheers Maurizio On Jul 14, 1:57 am, William Stein wrote: > On Wed, Jul 14, 2010 at 1:42 AM, Maurizio wrote: > > I just spend a couple of words about IDEs. I've personally spent a > > decent amount of time on Spyder and Eric, and my impressions are: > > - Eric is very well suited for general software development, it is not > > completely polished, and it lacks (at least explicitly, I didn't get > > those) useful features for scientific computing (which I'll later > > mention) > > - Spyder is theoretically exactly what I was looking for: it is a > > pythonized version of the Matlab GUI, which I felt very comfortable to > > use; nonetheless, the problems are there: > > 1) I find it very slow (even if I may have problems with matplotblib, > > my workstation is quad-core and generally fast), certainly slower than > > Eric (I think both are written in Python) > > 2) window management is awful: if you undock an internal subwindow, > > you are forced to not move it again within the area of the main Spyder > > window, otherwise it immediately redocks it > > 3) integrated plot management looks pretty, but (it's entirely not > > Spyder's fault) matplotlib just outputs pictures, so plot navigation > > is still orders of magnitude less evolved than Matlab's (I know it may > > sound silly, but is that so difficult to do something better??) > > on the pros side I count: > > 1) both internal and external console: the former one is useful to do > > experiments within the script you are editing, the latter is better to > > have a clean environment > > 2) variables management and browsing > > 3) enhanced editing (code completion, syntax highlighting, classes > > identification and browsing) > > Very interesting. > > 1. How does the speed of the Sage notebook running locally on your > computer compare to Spyder locally on your computer? > > 2. Are the plotting issues you mention the result of Spyder embedding > static png images (like the sage notebook does) or something more > subtle. The sage notebook might switch to HTML5 canvas rendering > soon I say might, because after having tried it a bunch, I'm > seriously concerned that HTML5 canvas matplotlib is slow -- > surprisingly, maybe much slower than using png's and image maps, which > we should have at least enabled long ago. > > 3. I have talked with people about making a Matlab-clone-ish version > of the Sage notebook. This would be web-based, but instead of feeling > Mathematica-like, it would feel much more Matlab-like. Thoughts? > > > > > I don't know what about outside Europe, but I find so strange that > > SAGE is unknown in scientific community, I find it very useful (from > > an engineering point of view), and I personally think that may be a > > perfect solution to be introduced inside universities at first
[sage-devel] Re: IDE's; science/engineering
Unfortunately, I have no log of this. I think that what we did was to make it run under the sage -sh shell, so that it was possible to do "from sage import *" at the beginning of any python file and achieving something pretty usable. Sorry for missing details Maurizio On 18 Lug, 02:29, "Nicolas M. Thiery" wrote: > On Wed, Jul 14, 2010 at 12:42:53AM -0700, Maurizio wrote: > > By the way, some > > time ago we managed to run spyder letting it use the sage console as > > interpreter, which was kind of fun, but never used it extensively. > > Did you keep a log of what exactly you did to achieve this? After > seeing an impressive demo of Spyder, I gave it a shot for a couple > hours and dropped the idea after fighting with too many little issues. > > Thanks! > > Cheers, > Nicolas > -- > Nicolas M. Thi ry "Isil" http://Nicolas.Thiery.name/ -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: IDE's; science/engineering
how do you get the new canvas with matplotlib 1.0? I installed it today, but from matplotlib.rcsetup.all_backends I don't get any item which looks like html5 canvas Maurizio On 14 Lug, 10:03, William Stein wrote: > On Wed, Jul 14, 2010 at 9:42 AM, Maurizio wrote: > > Hi > > >> Very interesting. > > >> 1. How does the speed of the Sage notebook running locally on your > >> computer compare to Spyder locally on your computer? > > > I don't think they can be comparable, doing so different functions... > > Anyway I always use notebook from a server in the local network (which > > is anyway pretty fast). And I still fear that my python installation > > in the windows virtual machine is somehow broken because the ipython > > console is much slower than the plain python console. By the way, some > > time ago we managed to run spyder letting it use the sage console as > > interpreter, which was kind of fun, but never used it extensively. > > Basically what we did was to install spyder on the server hosting > > SAGE, and then running Spyder logging on that machine from our > > workstation and exporting the display. That has been a very > > interesting experiments, but later I had little occasion to use it, > > and the notebook is still more comfortable for touch and go. > > >> 2. Are the plotting issues you mention the result of Spyder embedding > >> static png images (like the sage notebook does) or something more > >> subtle. The sage notebook might switch to HTML5 canvas rendering > >> soon I say might, because after having tried it a bunch, I'm > >> seriously concerned that HTML5 canvas matplotlib is slow -- > >> surprisingly, maybe much slower than using png's and image maps, which > >> we should have at least enabled long ago. > > > Yes, they embed static png images with image maps (if I understand > > what you refer to), which is standard matplotlib output nicely put > > inside a Spyder subwindow. The problem is that I strongly dislike this > > output form, I consider it like a fake form of interaction. Some time > > ago, we were considering to spend a little amount of time in writing a > > HTML5 canvas for matplotlib, but we stopped because of (apart not > > knowing how to interface with a server) doubts about matplotlib > > structure. > > As of matplotlib-1.0, there is now an HTML5 canvas for matplotlib. I > played around with it a bunch on Sunday. It'll be in Sage soon enough. > > > > > What I mean is that matplotlib is designed so that its > > canvas is just translating a bunch of lines and points and other > > graphical objects into something that is understood by the target > > viewer. To enhance real interaction, IMHO, the best way would be to > > pass to the viewer also an idea of the hierarchical structure of the > > plot, so that the viewer by itself is capable of changing basic > > properties like "axis visibiliy", "plot line colour", etc. At this > > point, I hope we were wrong and that HTML5 canvas that has been > > developed can overcome these problems. Anyway, I think that doing > > everything on the server side and letting the client only plot the > > received data may be too much communication overhead, while there are > > a number of different javascript viewers which are pretty powerful and > > fast. > > >> 3. I have talked with people about making a Matlab-clone-ish version > >> of the Sage notebook. This would be web-based, but instead of feeling > >> Mathematica-like, it would feel much more Matlab-like. Thoughts? > > > I think that SAGE-python can be easily accepted by Matlab users > > because of intrinsic similarity of scripting language structure, > > console interaction, and stuff like that. The problem is that Matlab > > is very reliable for operations like vector manipulation (which > > require additional interaction with numpy in SAGE), data analysis > > (there are many potential toolboxes in scipy) and symbolic analysis > > (for which SAGE is growing, but still very far from industrial-level > > reliability). > > On the filter design side, I agree that is very useful and often used, > > and I can tell that scipy has the signal toolbox which incorporates > > some functions to do this. I think that most of the engineering > > appealing that SAGE can show is currently strongly supported by numpy/ > > scipy power: if SAGE can be better integrated with them, and if we can > > improve their functions, things will improve for engineers. > > > At the moment, there may be very
[sage-devel] Re: IDE's; science/engineering
Hi > > Very interesting. > > 1. How does the speed of the Sage notebook running locally on your > computer compare to Spyder locally on your computer? > I don't think they can be comparable, doing so different functions... Anyway I always use notebook from a server in the local network (which is anyway pretty fast). And I still fear that my python installation in the windows virtual machine is somehow broken because the ipython console is much slower than the plain python console. By the way, some time ago we managed to run spyder letting it use the sage console as interpreter, which was kind of fun, but never used it extensively. Basically what we did was to install spyder on the server hosting SAGE, and then running Spyder logging on that machine from our workstation and exporting the display. That has been a very interesting experiments, but later I had little occasion to use it, and the notebook is still more comfortable for touch and go. > 2. Are the plotting issues you mention the result of Spyder embedding > static png images (like the sage notebook does) or something more > subtle. The sage notebook might switch to HTML5 canvas rendering > soon I say might, because after having tried it a bunch, I'm > seriously concerned that HTML5 canvas matplotlib is slow -- > surprisingly, maybe much slower than using png's and image maps, which > we should have at least enabled long ago. > Yes, they embed static png images with image maps (if I understand what you refer to), which is standard matplotlib output nicely put inside a Spyder subwindow. The problem is that I strongly dislike this output form, I consider it like a fake form of interaction. Some time ago, we were considering to spend a little amount of time in writing a HTML5 canvas for matplotlib, but we stopped because of (apart not knowing how to interface with a server) doubts about matplotlib structure. What I mean is that matplotlib is designed so that its canvas is just translating a bunch of lines and points and other graphical objects into something that is understood by the target viewer. To enhance real interaction, IMHO, the best way would be to pass to the viewer also an idea of the hierarchical structure of the plot, so that the viewer by itself is capable of changing basic properties like "axis visibiliy", "plot line colour", etc. At this point, I hope we were wrong and that HTML5 canvas that has been developed can overcome these problems. Anyway, I think that doing everything on the server side and letting the client only plot the received data may be too much communication overhead, while there are a number of different javascript viewers which are pretty powerful and fast. > 3. I have talked with people about making a Matlab-clone-ish version > of the Sage notebook. This would be web-based, but instead of feeling > Mathematica-like, it would feel much more Matlab-like. Thoughts? > > I think that SAGE-python can be easily accepted by Matlab users because of intrinsic similarity of scripting language structure, console interaction, and stuff like that. The problem is that Matlab is very reliable for operations like vector manipulation (which require additional interaction with numpy in SAGE), data analysis (there are many potential toolboxes in scipy) and symbolic analysis (for which SAGE is growing, but still very far from industrial-level reliability). On the filter design side, I agree that is very useful and often used, and I can tell that scipy has the signal toolbox which incorporates some functions to do this. I think that most of the engineering appealing that SAGE can show is currently strongly supported by numpy/ scipy power: if SAGE can be better integrated with them, and if we can improve their functions, things will improve for engineers. At the moment, there may be very little advantage of using SAGE instead of plain python to interface with numpy/scipy, which are anyway the core toolboxes needed. Maurizio > > > I don't know what about outside Europe, but I find so strange that > > SAGE is unknown in scientific community, I find it very useful (from > > an engineering point of view), and I personally think that may be a > > perfect solution to be introduced inside universities at first (thanks > > to the wonderful internet-based notebook system). > > I was also very surprised. But it is simply a fact I observed. Well, it > wasn't > so much that Sage is *unknown* -- many people knew about it. What I > noticed at Euroscipy is that very few of the people there used Sage. > Not a single speaker > (except me) said they used Sage, and there were nearly about speakers > (including > lightning talks). > > > The problem I see now regarding scientific computing, is the not so > > seamless integration of numpy-scipy: do you think SAGE m
[sage-devel] Re: IDE's; science/engineering
I just spend a couple of words about IDEs. I've personally spent a decent amount of time on Spyder and Eric, and my impressions are: - Eric is very well suited for general software development, it is not completely polished, and it lacks (at least explicitly, I didn't get those) useful features for scientific computing (which I'll later mention) - Spyder is theoretically exactly what I was looking for: it is a pythonized version of the Matlab GUI, which I felt very comfortable to use; nonetheless, the problems are there: 1) I find it very slow (even if I may have problems with matplotblib, my workstation is quad-core and generally fast), certainly slower than Eric (I think both are written in Python) 2) window management is awful: if you undock an internal subwindow, you are forced to not move it again within the area of the main Spyder window, otherwise it immediately redocks it 3) integrated plot management looks pretty, but (it's entirely not Spyder's fault) matplotlib just outputs pictures, so plot navigation is still orders of magnitude less evolved than Matlab's (I know it may sound silly, but is that so difficult to do something better??) on the pros side I count: 1) both internal and external console: the former one is useful to do experiments within the script you are editing, the latter is better to have a clean environment 2) variables management and browsing 3) enhanced editing (code completion, syntax highlighting, classes identification and browsing) I don't know what about outside Europe, but I find so strange that SAGE is unknown in scientific community, I find it very useful (from an engineering point of view), and I personally think that may be a perfect solution to be introduced inside universities at first (thanks to the wonderful internet-based notebook system). The problem I see now regarding scientific computing, is the not so seamless integration of numpy-scipy: do you think SAGE may improve numpy arrays management with cleaner syntax than regular python? I know you are usually against introducing syntax that is unacceptable in standard python, but I think that allowing users to avoid writing "np.array()" to do any kind of vector manipulation would be highly appreciated! I strongly support SAGE for science!! :) By the way (not completely off-topic) a colleague of mine is having some troubles in working with scipy.optimize within SAGE, but I have no details right now... I should better check! My 2 cents Thanks Maurizio On 11 Lug, 20:41, Ondrej Certik wrote: > On Sun, Jul 11, 2010 at 3:20 AM, William Stein wrote: > > Hi, > > > 1. IDE's > > There are a number of IDEs that can be used for Python development: > > > * Spyder (free, cross platform) --http://code.google.com/p/spyderlib/ > > * Eric (free, cross platform) --http://eric-ide.python-projects.org/ > > * PyDev + Eclipse or Aptana (free, cross platform) --http://pydev.org/ > > * Wing IDE (non free, but has a 30-day trial) --http://www.wingware.com/ > > * XCode (free, closed, OS X only) > > > I'm at EuroScipy and many of the scientists and engineers giving talks > > mention some of these IDE's (especially Spyder). It would be of > > interest to make a page athttp://wiki.sagemath.orgabout each of the > > above IDE's in the context of Sage. Which can be used with Sage? > > How? Do they work on anything but Linux, etc. Any volunteers? This > > could be a good student project (so possibly some funding for > > something at UW). > > > 2. Sage at EuroScipy: > > > Another thing -- though most talks mention Cython, not one single talk > > given about actual engineers/scientists doing work even mentioned Sage > > -- and there were over 30 talks. Perhaps there is no penetration at > > all of Sage into scientific computing, at least in Europe. Perhaps > > this will change in the next few years, given that NSF looks highly > > likely to fund this NSF granthttp://wstein.org/grants/compmath09/ > > > Sage was only mentioned in the first keynote by Langtangen, in which > > he explained that installing Python for his students is very hard. > > His personal solution -- force the students to install Ubuntu, either > > natively or in a Virtual Machine. Full stop. > >http://picasaweb.google.com/wstein/20100710EuroscipyDay1#549240022431... > > He made some (funny) jokes about being a dictator. > > > I personally disagree with his suggested "solution". Maple, Matlab, > > Mathematica do better, and so can we. > > Yeah, definitely. I am now working at the Lawrence Livermore National > Lab during the summer and I don't have a root access to my computer, > and it is not running Ubuntu. So his solution would be a complete > fail
[sage-devel] Re: Should there be some *good* examples on notebook?
Hi all On Feb 24, 2:24 pm, "Dr. David Kirkby" wrote: > Oscar Lazo wrote: > > > On 23 feb, 10:39, "Dr. David Kirkby" wrote: > >> If one sets up a Sage server for public use, there is the opportunity for > >> someone to publish worksheets, there is a section: > > >> "Browse published Sage worksheets > >> (no login required)" > > >> But often those worksheets are bad examples, error message, or just plain > >> people > >> experimenting. I do not think they generally reflect well on Sage. > > >> Hence I'd propose that there was a collection of worksheets that always > >> appeared > >> at the top, with sensible names and good examples. Then let the other > >> published > >> worksheets be shown below. > > >> Either that, or perhaps make it clear that anyone can edit these > >> worksheets, and > >> so many not represent how best to use Sage. > > >> One normally associates "published" work as being of high quality. But in > >> this > >> case the "published" can be anything. Whilst regular users of Sage will > >> know > >> what this means, for someone taking a quick glance, they are likely to get > >> the > >> wrong impression. > > > I strongly agree! I remember taking the bad impression you described > > when I first saw the published worksheets on sagenb.org . > > I'm glad I'm not the only one to feel this. > > > I don't > > think a rating system would work since there is already one, and it > > rarely gets used, sometimes good worksheets get bad rankings and vice > > versa. I think it would be best if people would just submit proposed > > worksheets for inclusion in the *good* category. > > Yes, agreed. > > Jaap Spies sent me a screen shot some time back, when I first set up a Sage > server on my own SPARC machine. I thought it was pretty impressive, so took > his > code and published it on the server running on 't2'. > > http://t2nb.math.washington.edu:8000/home/pub/3/ > > But there is also a published document which shows an error message, which has > since been resolved > > http://t2nb.math.washington.edu:8000/home/pub/1/ > > so that does not give a good impression (This is not aimed at a dig at Robert > who published it. He was trying to show me a problem. It's just an example of > the sort of things that get "published" ) > > > I further propose that some of these get included in new Sage notebook > > installs, so that people new to the notebook can inmediately click on > > already made notebooks and get some nice code that works. > > Yes, I think 30+ decent examples. Hopefully some where you do not need a > degree > in maths to know what they are about. > I totally agree that good worksheet examples would be very useful for many reasons: having examples, learning small pieces of code from experienced users, getting a good first impression, etc etc. > I'm not a mathematician, but have an engineering background. When I look at > the > introductory examples for Mathematica, most are easily understood - graphs > plotting, factorization, integration, differentiation, numerical methods, > finding roots, curve fitting to data, etc. > > I think there is a bit too much emphasis of the examples of things only > understandable by those with a very good maths background. I've never before > come across the term "ring". To be a viable alternative to the Mathematica at > least, there needs to be more examples of usage by non-mathematicians. > > Dave I strongly agree on this! Even if there's nothing wrong with current emphasis, I think that there's a lot of potential in non-mathematics, but other sciences related users. For example, just having good examples of the well working integration with numpy and scipy would be very useful, maybe also to catch other problems :) I have still not a clear idea on which would be a good test case, but ideally a notebook with some symbolic calculation (using pynac, maxima or sympy) and further numerical evaluation using large arrays (using numpy) and possibly also scientific functions, would be VERY attractive, at least to many people I know. Regards Maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: notebook improvement
ok, still me :P I've found the relevant ticket http://trac.sagemath.org/sage_trac/ticket/7501 now I'll try to apply the patch. it seems to me that this is actively worked on, and there should be some draft code on someone else's computer, so I am probably not any helpful here. cheers maurizio On 17 Feb, 22:24, Maurizio wrote: > I am sorry, > yesterday I started to work on this, but I was working on sage 4.2 > today I updated to sage 4.3.2, but I also noticed that in the > beginning of the file cell.py it is stated that it is part of the OLD > sage notebook... > now I should understand where to look again :) > > maurizio > > On 17 Feb, 21:59, Maurizio wrote: > > > hi all, > > I do not want to set any expectation, but I'd take some help with a > > small experiment > > I wanted to try to introduce codemirror in the notebook. as previously > > suggested by this list, it seems the most mature solution for syntax > > highlighting. I have tried myself bespin, and it is very feature-less > > at this stage. on the other hand, it has the very appealing feature of > > being a self-contained single .js file. > > > anyway, codemirror looks good, so I wanted to give it a try. > > I have two problems: > > 1) which functions exactly should I modify, to do it? I was having a > > look at the function html_in() in the file cell.py into /sage-4.3.2- > > linux-64bit-ubuntu_9.10-x86_64-Linux/devel/sage/sage/server/notebook. > > I am not sure that has been effective, where does the html a code for > > a new cell comes from? > > 2) where should I ideally put the javascript and css files necessary? > > how do I reach them within the path recognized by the html page? > > > the good thing of codemirror, is that it is just a script to be > > applied on a textarea within a div: doesn't that already match with > > the current status of a cell? > > > thanks a lot > > > maurizio > > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: notebook improvement
I am sorry, yesterday I started to work on this, but I was working on sage 4.2 today I updated to sage 4.3.2, but I also noticed that in the beginning of the file cell.py it is stated that it is part of the OLD sage notebook... now I should understand where to look again :) maurizio On 17 Feb, 21:59, Maurizio wrote: > hi all, > I do not want to set any expectation, but I'd take some help with a > small experiment > I wanted to try to introduce codemirror in the notebook. as previously > suggested by this list, it seems the most mature solution for syntax > highlighting. I have tried myself bespin, and it is very feature-less > at this stage. on the other hand, it has the very appealing feature of > being a self-contained single .js file. > > anyway, codemirror looks good, so I wanted to give it a try. > I have two problems: > 1) which functions exactly should I modify, to do it? I was having a > look at the function html_in() in the file cell.py into /sage-4.3.2- > linux-64bit-ubuntu_9.10-x86_64-Linux/devel/sage/sage/server/notebook. > I am not sure that has been effective, where does the html a code for > a new cell comes from? > 2) where should I ideally put the javascript and css files necessary? > how do I reach them within the path recognized by the html page? > > the good thing of codemirror, is that it is just a script to be > applied on a textarea within a div: doesn't that already match with > the current status of a cell? > > thanks a lot > > maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] notebook improvement
hi all, I do not want to set any expectation, but I'd take some help with a small experiment I wanted to try to introduce codemirror in the notebook. as previously suggested by this list, it seems the most mature solution for syntax highlighting. I have tried myself bespin, and it is very feature-less at this stage. on the other hand, it has the very appealing feature of being a self-contained single .js file. anyway, codemirror looks good, so I wanted to give it a try. I have two problems: 1) which functions exactly should I modify, to do it? I was having a look at the function html_in() in the file cell.py into /sage-4.3.2- linux-64bit-ubuntu_9.10-x86_64-Linux/devel/sage/sage/server/notebook. I am not sure that has been effective, where does the html a code for a new cell comes from? 2) where should I ideally put the javascript and css files necessary? how do I reach them within the path recognized by the html page? the good thing of codemirror, is that it is just a script to be applied on a textarea within a div: doesn't that already match with the current status of a cell? thanks a lot maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: syntax highlighting in the notebook
Maybe I should not talk because I have no idea on how CodeMirror and BeSpin work, but I would say that I'd think more than twice before choosing CodeMirror instead of BeSpin, for this reason: 1) BeSpin is anyway sponsored (or at least hosted) by Mozilla, which is a fairly decent guarantee of mid-term support and a huge amount of advertisement 2) BeSpin seem to have (looking at number of members and posts in the respective google groups) more users and activity around it 3) even if now BeSpin suffers some feature lack, that should be caused by a major refactoring happened between 0.4 and 0.6 version. the important features should be back in 0.7 soon My 2 cents Regards Maurizio On 4 Feb, 06:52, Jason Grout wrote: > On 02/03/2010 09:33 PM, Alex Leone wrote: > > > Mozilla Bespin[1], which is an browser-based IDE with syntax > > highlighting etc, recently released an easy way to embed the editor in > > your own web pages. I'll look into how hard it would be to use in > > Sage. It's still pretty alpha. > > What abouthttp://trac.sagemath.org/sage_trac/ticket/7501? > > Thanks, > > Jason -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: SAGE future add-in recommendation
On 21 Gen, 00:22, William Stein wrote: > On Wed, Jan 20, 2010 at 1:33 PM, Maurizio wrote: > > Hi all, > > even if in the recent times I've been much less involved with SAGE, I > > just wanted to point out two pieces of software that I hope could > > become useful in the next future for SAGE. > > The first is Bespin, the Javascript code editor by Mozilla. It has > > very recently been released under GPL. Unfortunately, it is lacking > > syntax highlighting now (I don't know why, probably a regression, > > which is planned to fix anyway), but I think it could be worth a try. > > Mozilla development looks like a good warrantee :) > >https://mozillalabs.com/bespin/ > > Have you used Bespin personally much? I've tried it about 5 months > ago and couldn't think of any way to make any use of it for Sage. > What did you have in mind? > Actually I didn't. I just considered it as the best way to get syntax highlighting and other coder-related stuff at the cheapest cost. > > > > The second is Acire. It is in a very early stage of development, but I > > think the concept could be useful to SAGE users. Basically, it > > provides a set of code snippets (it is aimed to Python and maybe to > > PyGTK), which I consider pretty useful for beginners and sometimes > > also for quite experienced users. Maybe SAGE could have its own set of > > categorized snippets. > >http://www.jonobacon.org/2010/01/12/acire-0-2-released/ > > Interesting. > > William Sorry, I didn't mention that I didn't use any of those software, but I wanted to make everybody aware of them because they seem useful at least in theory :) -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] SAGE future add-in recommendation
Hi all, even if in the recent times I've been much less involved with SAGE, I just wanted to point out two pieces of software that I hope could become useful in the next future for SAGE. The first is Bespin, the Javascript code editor by Mozilla. It has very recently been released under GPL. Unfortunately, it is lacking syntax highlighting now (I don't know why, probably a regression, which is planned to fix anyway), but I think it could be worth a try. Mozilla development looks like a good warrantee :) https://mozillalabs.com/bespin/ The second is Acire. It is in a very early stage of development, but I think the concept could be useful to SAGE users. Basically, it provides a set of code snippets (it is aimed to Python and maybe to PyGTK), which I consider pretty useful for beginners and sometimes also for quite experienced users. Maybe SAGE could have its own set of categorized snippets. http://www.jonobacon.org/2010/01/12/acire-0-2-released/ By all Maurizio -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: Which software to write Sage code ?
I honestly didn't get the chance to work with it, but when I installed sage-mode in emacs, I found it very useful, because it does this integration of a powerful editor (also sufficiently newbie friendly) with a sage embedded terminal Try sage-mode and emacs!! :) Maurizio On 17 Nov, 17:31, Jan Groenewald wrote: > Hi > > Something in between the IDE (eclipse, spe, idle, whatever) > and the text editor (YaY vim!) that is very newbie friendly is gedit > with an embedded terminal (which we use to teach) with ipython > (or sage) in the embedded terminal. It is the standard gnome > terminal, and needs gedit-plugins to be installed for the embedded > terminal to be available. > > It has ctl-tab, ctl-shift-tab for editor<->terminal focus, > usual ctl-c, ctl-x, ctl-v keys for copy/cut/paste, syntax > highlighting, search and replace, line numbers, bracket highlighting, > etc. though no function completion or tab completion, but we > have the ipython in the embedded terminal for that. > > regards, > Jan > > -- > .~. > /V\ Jan Groenewald > /( )\ www.aims.ac.za > ^^-^^ -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
[sage-devel] Re: PPA for Sage in Ubuntu
Hi, let me give a quick reference for starting with ppa: http://blog.bodhizazen.net/linux/launchpad-ppa-tips/ regards Maurizio On Oct 24, 5:30 pm, Jason Grout wrote: > The IRC logs show a recent conversation (again) about Sage packaging for > Ubuntu. We all know it would be a massive amount of work to update > things, which almost no one knows how to do. > > @debian experts: Is it easy to make a PPA package for Sage and put it on > launchpad? > > We tell people it's easy enough to just download the binary, unzip, and > run it. But it seems just a tad bit easier (and much more comfortable) > if someone can just add something to their apt sources and get automatic > updates, etc. I know that if I have a choice between installing a > package and installing a PPA, I usually use the PPA since it is > automatically updated. > > Thanks, > > Jason > > -- > Jason Grout --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: What about Sage Conservative version?
I have not taken any offense, on the contrary! Thank you very much for your detailed answer. Maurizio On Oct 27, 10:41 pm, William Stein wrote: > On Tue, Oct 27, 2009 at 1:58 PM, Maurizio wrote: > > > What about adopting a simpler strategy? > > What do you think about this: every 6 months (or 9, or 12 whatever), > > the developers are asked to focus on producing bugfixing instead of > > introducing new features. > > Asked by whom? For how long? And, who are "the developers"? The > Sage project has no fulltime employees: Michael Abshoff was the only > one we ever had, and his funding ran out in May. The vast majority > of people who work on Sage do so for very specific reasons related to > their own research or teaching, and consequently they work on > specifically what they want to work on. Moreover, I try my best not > to boss anybody around involved in the project (if anybody feels > bossed around by me, definitely let me know -- it's not intentional). > > I personally would be uncomfortable telling "the developers" to focus > for a month (say) on producing bugfixes instead of new features. > However, I think there is value in thinking about specific ways to > improve the quality of Sage overall. There are many things we can all > do to help. Here are some concrete suggestions: > > 1. Improve the doctest coverage. It is currently 79.5%: > $ sage -coverageall > Overall weighted coverage score: 79.5% > Total number of functions: 22734 > We need 114 more function to get to 80% coverage. > -- > > TAKE ACTION: Anybody reading this right now could sit down and put a > dent in that "114 more functions". > > 2. Report bugs. I checked yesterday and there are 822 known bugs in > Sage, according to trac. If you find a bug, make sure to report it > and get it into trac. Don't just blow it off. The more bugs we know > about (with clean, easy to test reproducible examples!), the better. > > TAKE ACTION: I bet you know about one bug in Sage that isn't listed in > trac -- report it, and make sure it gets listed there! > > 3. Organize a bug day. A few years ago Martin Albrecht introduced a > "Bug Day" idea into Sage development. This is a pre-announced day > when people meet on irc and fix bugs. We have had 17 of these, but > they stopped for no apparent reason nearly a *year* ago. See the list > here:http://wiki.sagemath.org#BugDays > > TAKE ACTION: Organizing a Bug Day is easy! Just come up with a time, > announce it on sage-devel, see if you can get some other people > interested, make a list of specific bugs to work on (with some common > theme), show up, "keep score", and report on what happened in another > sage-devel followup email. > > 4. Help write a Selenium test suite for the sage notebook. If we had > a sufficiently good one, this would have prevented most (all?) of the > many recent issues with the notebook. I personally won't do any > nontrivial further development on the notebook or merging of patches > until there is a test suite. > > TAKE ACTION: I'm going to do this. > > > In this way, what happens is that one > > release every "n" months could be considered more stable and reliable, > > and these releases are kept on the website available for downloading > > together with the current release. > > In this way, I hope, there's really no overhead in the current work. > > This is trying to introduce some committee-style rules into the future > of Sage development, instead of suggesting specific concrete actions > people can take to improve the quality of Sage. This makes me a > little bit uncomfortable, as if I'm being told what to do. It also > seems idealistic to ask a hundred people to work a few weeks on fixing > bugs -- "the developers are asked to focus on producing bugfixing > instead of introducing new features" -- and assume that this will > result in "no overhead" and a release that is "more stable and > reliable". My concerns are that: > > (1) This suggestion asks many people to do for free a bunch of > painful, difficult work that they likely don't want to do, and don't > have the time to do. > > (2) Without a top notch test suite and multiple rounds of alpha/beta > testing, often fixing a bunch of bugs can easily results in software > that is less stable and more buggy. I think Sage has a good test > suite, but honestly it is nowhere near where I want it to be -- which > is 100% doctest coverage, plus a large suite of randomized testing > that is run 24/7 on a cluster hunting for bugs, like what is done in > the MPIR project.
[sage-devel] Re: What about Sage Conservative version?
What about adopting a simpler strategy? What do you think about this: every 6 months (or 9, or 12 whatever), the developers are asked to focus on producing bugfixing instead of introducing new features. In this way, what happens is that one release every "n" months could be considered more stable and reliable, and these releases are kept on the website available for downloading together with the current release. In this way, I hope, there's really no overhead in the current work. Of course, some effort in changing goals twice a year would be required, so that old problems are solved. Thanks for discussing this Regards Maurizio On 27 Ott, 17:54, William Stein wrote: > On Tue, Oct 27, 2009 at 1:36 AM, Minh Nguyen wrote: > > > Hi folks, > > > On Tue, Oct 27, 2009 at 5:22 AM, William Stein wrote: > > >> Hi, > > >> I wonder why everybody (*) making suggestions has never put together a > >> single Sage release themselves, yet everybody who has done significant > >> work putting together Sage releases, organizing the web page, mirror > >> binaries, etc., has completely refrained from making any suggestions? > > > I have two excuses. > > > Lame excuse: I was busy preparing a draft of my Honours thesis. > > > Good excuse: I wanted to spend some time gathering my thoughts on the > > issue of maintaining a conservative series of releases. Here are my > > thoughts. > > > Let's imagine for the sake of discussion that we have two separate > > releases. On the one hand, there is a conservative double point > > release series like Sage 4.2.x which only have bug fixes and also bug > > fixes that have been back ported from major releases. Such bug fixes > > include fixing bugs in the Sage standard library, bug fixes in the > > Sage standard documentation, updating standard packages but not > > upgrading spkg's to upstream releases, etc. On the other hand, we have > > a major single dot release like Sage 4.x which includes new features > > in addition to bug fixes that have been back ported to the Sage 4.2.x > > series. Furthermore, both the double dot point and major releases are > > released more or less roughly at the same time. For something close to > > what I'm talking about, refer to the current situation with Python in > > which there is a maintenance release for Python 2.6.x, and at the same > > time there is a major release (i.e. Python 3.x) that includes new > > features and backward incompatible changes. > > I don't see the Python 2.x series as just a maintenance/bug fix > series. The difference between 3.x and 2.x is that 3.x made major > backward incompatible changes to 2.x. But 2.x still sees nontrivial > new development, packages, functionality, etc. > > An analogous project might be how the Linux kernel used to have a > stable and unstable version at the same time. In Linux development > they realized that entire approach was a huge mistake and got rid of > it. (Some people might not be old enough to remember this.) > > Another analogy might be PARI, which also has a stable and unstable > release. These evidently merge every 3-4 years or so, and I've been > told by many people (including the lead dev of pari) that it is a bad > idea to use the stable release, unless you have no choice. (He > repeatedly strongly recommend we switch to the unstable version for > Sage last time I visited him in Bordeaux.) > > Another analogous project would be Ubuntu, which has both say 9.10 > (any moment now), and 8.04.LTS. Probably the LTS releases of Ubuntu > are the most successful project I can think of right now as far as > stable/unstable goes. This is also nice because a Linux > distribution is more analogous to Sage than some of the other projects > above. > > William --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: What about Sage Conservative version?
My answer to William Stein's question is double: first of all, I think that sometimes people less involved than being active developers can give suggestions from another perspective, and I hope that those are not considered useless simply because they are given from people which are not contributing (contributing is not just writing code, right?). More than that, I was supposing that this problem of making available for some more time releases that are a little less bug prone, could have been not noticed from people involved with every day development. This is absolutely understandable, but I think that it could be valuable to consider other points of view as well (especially if it could cover some significant part of the users). My point of view is in complete accordance to what Marshall Hampton said: "Having something like no spkg upgrades or other major revisions as a guideline for double point releases would help too. Maybe it would be not too much extra work to schedule such a release once a year? It could happen unplanned more than that, but it could be a good prelude to a release with more changes. Such a minimal release should be easier than most, so ideally it could happen quite quickly. " As regards Nick Alexander's comment, I do also think that this strategy has been working, but this doesn't mean that it cannot be improved with very little effort. I don't think this would be a great change into developer's mind, but maybe just some fine tuning. I hope this amount of changes can be discussed openly, and that everybody can help in this process. Regards Maurizio On 26 Ott, 20:37, Nick Alexander wrote: > On 26-Oct-09, at 11:22 AM, William Stein wrote: > > > > > Hi, > > > I wonder why everybody (*) making suggestions has never put together a > > single Sage release themselves, yet everybody who has done significant > > work putting together Sage releases, organizing the web page, mirror > > binaries, etc., has completely refrained from making any suggestions? > > I didn't spend significant time, but I did spend an entire week being > release manager once. > > It is my personal opinion that the system has been working. I was > disappointed that major backwards incompatibility was lost to a double- > point upgrade, but that's infrequent. I opted out of this discussion > because no matter what is agreed to, I don't see anything changing: > Sage is, for better or for worse, driven by developers. All talk of > releases marked stable, etc, doesn't fit with that reality. > > Nick --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: What about Sage Conservative version?
Thank you Rob, you seem to have caught my point 100%, I completely agree with your comments Maurizio On Oct 26, 1:06 am, Rob Beezer wrote: > We have a Sage server on our campus. We don't have departmental > sysadmins, instead it is maintained by the same folks who do the > administrative systems for the whole campus. I can probably only > reasonably expect two upgrades a year from them, at most. Once in the > summer and maybe over the winter break between semesters (that's > Northern Hemisphere time). I have a good idea which version to > recommend, but not everybody is going to be paying as close attention > as I do. So I think it would be extremely helpful to > > (a) note somewhere in the download section your best bet (ie version > number) for a six-month or twelve-month installation (and keep it > easily available). > > (b) give some careful thought to the design of a release that would > help make (a) work well. > > For example, this summer the symbolics switchover from May/June began > to stabilize, and the intense notebook upgrade didn't begin until > September. So if a release sometime in August was targeted to be > super-stable for the purpose of part (a), that might be useful to > folks whose installations can't change as quickly as Sage development > progresses. > > The above does not require extra maintenance - just a bit more > foresight and planning in the release schedule (which I realize is > subject to a variety of pressures, such as the availability of release > managers and the unpredictability of new code, timely reviews, OS > upgrades, etc, ...) > > Rob --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: What about Sage Conservative version?
One of the main point I took into account was the necessity of not adding a significant amount of work to the community, actually. Basically, my only point was aimed to take advantage of something that I think we already have, but that we don't value enough right now. As I see it, I think that it could probably be a good idea to slightly change the download page, as the user is provided the choice of which version of Sage to download: either the Sage "current release" which provides all the exciting new features, constantly updated, or the Sage "conservative release", which is somehow poorer in terms of features, but it's more polished in the corners of what is in it. If, as I understood it (I might be wrong), this kind of releases already take place once in a while (which I think, make a lot of sense), it is just a matter of underline them and make them available for a little longer, and contemporary to the other current releases which happen in the meantime. I think that out there there are a lot of people which would consider VERY useful to get a slightly older software, but with increased stability and reliability, and I don't think there's something wrong with it. I think that in this way a lot of people could join the community, and help as well, without the need of being very active developers at the same time; that would allow this kind of people to use Sage for their current work (because they can access to a very reliable release), and provide something back in the long term (as you know, it's very easy to become addicted!). I don't even think the "conservative" should be considered Long Term Support releases (in the sense that we should backport all the bug fixing to those releases); I know that also "conservative" releases can have bugs, but this doesn't mean we have to fix'em all with the consequence of slowing down the development. Do you think it would be so much overhead to check if the upgrade from the previous "conservative" release to the next one works correctly? Shouldn't it come almost directly from checking the working upgrade of every single current version? Best regards Maurizio On 25 Ott, 15:48, William Stein wrote: > On Sat, Oct 24, 2009 at 10:17 PM, Robert Bradshaw > > > > wrote: > > > On Oct 24, 2009, at 7:10 PM, Jason Grout wrote: > > >> mhampton wrote: > > >>> One thing that was mentioned on another thread is that the version > >>> number for sage-4.1.2 was quite misleading. It would help a lot if > >>> the version numbers were more grounded in reality. One simple change > >>> might be to not pick the version number until a final release has > >>> been > >>> decided on. Perhaps we could call the next release "sage-next" until > >>> it is finalized. > > >> +1 > > > +1 from me too. > > -1 from me, from both a social and technical perspective. > > 1. Technical: It will be a huge amount of work and introduce all kinds > of bugs (technically) if we call the next release "sage-next" instead > of what it will actually be, and I suspect it will be confusing > (socially) as well. As just one example, if you were to upgrade > Sage from version 4.1.2 to version "next", then upgrading to version > 4.2 from "next" would be completely broken. > > 2. Social: It is very common for trac comments, comments in source > code, discussion in email, etc., to have references such as "this > fixes a problem in sage-x.y.z.alpha2", or "this was merged into > sage-x.y.z.alpha3", or "we fixed this in sage-x.y.z.alpha1 so expect > to see this in sage-x.y.z when it is released". There are hundreds of > such comments connected with every single release. All such comments > become meaningless if x.y.z is replaced by "next". > > Neither of these problems is insurmountable. But I don't have the > time or inclination myself to surmount them. > > -- William --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] What about Sage Conservative version?
Hi all, let me share with you some thoughts. I know that this community likes a lot the strategy "release soon, release often"; I tend to like this as well. What I don't like, altogether, is the chance to have once in a while a quite buggy release on our way, which is, in my opinion, not unlikely with this strategy. Some examples are when big new features are introduced, like new symbolics, new notebook, new whatever else. From one point of view, having the current official release providing the brand new features, is useful in term of bug tracking (they are discovered much faster). On the other hand, if people are not intending to help and join the community, but just try testing a piece of software, they could get really annoyed by finding more or less trivial bugs (lots of them can pass not caught by a very careful review!) and make very bad advertisement. At the end of the day, provided that the community would keep releasing this way, why don't you also consider providing a "Conservative" release? That should simply represent a release where most (or the total amount) of the work is focused on fixing bugs, regressions, and known issues, rather than providing new features. I know this already happens once in a while, but I think that those release are simply not valued enough! That could be released in many ways: one every six months, one per year, also whenever it's ready can be a very good choice. For example, from my point of view (my knowledge is limited) 3.4.2 has been a pretty reliable release, all the efforts were in fixing stuff before getting the brand new 4.0. Another conservative release will probably be the 4.2, where the new symbolic stuff is already quite integrated and the new notebook will get a good finishing after the feedbacks from the 4.1.2 (also the backward compatibility break of the sws format has been restored, I think, which is good). So, the amount of time from two very casual conservative releases has been around 6 months, which is reasonable for productive oriented environments. In this way, first time users could be pointed to the conservative release, and once they get hungry and wants to get their hands dirty, they won't have problems in switching to the current release. This would also allow people that are very interested in short term results, to work with a fairly reliable release, rather than fearing that something goes wrong because of a simple bug, and discovering it just one day before the deadline (if not worse!). I hope this will be useful to the community. Best regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: new virtualbox image!
> I have been wondering whether we should start over and create a > (fairly minimal) ubuntu 9.10 install using squashfs and unionfs? What > do you think? There are a lot of good ideas in the approach of Puppy > Linux... but that doesn't mean we actually have to use it in the long > run. > > I wonder how big a minimal ubuntu 9.10 with Virtualbox Tools squashed > would be? I'm guessing around 600MB compressed. That might be OK. > I'm curious what your thoughts are. > > -- William > I don't see any reason why shouldn't we try using Ubuntu basis instead of Puppy Linux. I mean, maybe starting from "alternate" or "server" iso, instead of the "desktop" version of Ubuntu, could allow for better package shaping and results in minimal size, but apart from that, having a minimal working Ubuntu (or any other vastly widespread distribution) to me is much less prone to problems, in the sense that there is also much more support on Internet, because of the wide adoption. My 2 cents Maurizio --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Graphical Physics Program Suggestions
I don't want to add confusion, but I hope you can also think about the similarity between mechanical and electrical problems. After all, it's always matter of solving differential equations, having voltage, current, and so on, instead of mechanical quantities. The good thing, from this perspective, is that you could take some inspiration from the hundreds of SPICE tools, which already provide a GUI to define electrical problems. If you transpose the analogous of a netlist into something mechanical, you maybe already have a good starting point, which also gives you compatibility to electrical problem (which I would like :P). Just to give a rough idea, you could read: http://www.analog-europe.com/207200675 (this is just after some google search, but there are thousands of references about circuit solvers). The good thing, in my opinion, is that there is already a standard notation for netlists. Maybe you could introduce the mechanical equivalent of those :) Regards Maurizio On 23 Ott, 22:05, kstueve wrote: > Have any of you heard of Erik Neumann? He published some excellent > Java physics demos athttp://www.myphysicslab.com/ He is in Seatle, > and has attended UW. > > I have been looking into vector graphics with javascript. It appears > that circles, lines, and other curves are made out of lots of div > elements (to represent pixels and groups of pixels), most likely using > a third party library, such as jsDraw2D > (seehttp://ajax.phpmagazine.net/2009/04/jsdraw2d_javascript_graphics_l.html). > > Kevin --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Again about translation
Hi all, I just would like to raise your attention to tools that could help improving the translation process. How is it now managed? By using trac directly? I'd like to point out Transifex: http://www.transifex.net/ ( http://transifex.org/browser/README ) 8 Transifex is a highly scalable localization platform with a focus on 9 integrating well with the existing workflow of both translators and developers. 10 11 It aims in making it dead-simple for content providers to receive quality 12 translations from big translation communities, no matter where the project 13 is hosted. 19 Goals 20 - 21 22 * Provide an interface for translators to submit translations to multiple 23projects, regardless of the type of the underlying VCS 24 25 * Reduce the overhead a project maintainer usually undertakes to administrate 26accounts for translators 27 28 * Help translators do more by eliminating the need to subscribe to each VCS and 29learn its commands and tricks 30 31 * Encourage collaboration between developers and maintainers and thus, increase 32the language coverage of the participant projects It is python based, highly open-source and collaboration oriented, and supports different version control systems (including Mercurial), with the aim of making translation process effective and transparent. I'm not at all expert in this field, so I don't know if there are better tools out there, but maybe providing a service like this could improve the translation process a lot. Think about that Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: New Features! Updated live notebook. Support for Sage!
I don't understand: which is the difference between this codenode and our new notebook? Did we manage to get two brand new (but different) notebooks at the precisely same moment? This would be good in some sense, but also bad, if you know what I mean for avoiding waste of efforts Regards Maurizio On 17 Ott, 00:04, Dorian Raymer wrote: > Hello everyone, > We have merged a big development effort into the master > repository<http://github.com/codenode/codenode> > ! > > This represents a milestone in the ongoing effort to bring the whole design > to a new stable point. The Frontend was re-implemented using Django earlier > this year, and we now have completely re-done the Backend! > > High level features: > - Engine plug-ins > An engine is the computation process behind the notebook (Before today, > Codenode only supported the regular Python engine). > Engine types can be added without modifying library code! > - Sage Engine > Template engine type for using Sage in codenode! > - Admin management of Backends > A frontend can be associated with any number of backend servers, running > anywhere on the network. Each of those backend servers can support any > number of engine types. > - Development version of servers > Improved work flow; development of running code. Raw support for reloading > of modules with out restarting the process. > > Updated documentation <http://codenode.org/docs/>. These still need work, so > please make as many comments and ask as many questions as you have. This > will aid improving the quality of the documentation greatly. > > Updated live public notebook <http://live.codenode.org>, with two engine > types: Python and Sage!!! This backend server is also much more powerful > than what we had running on app engine. This makes the live site an actually > useful service, so please use it for day to day python/sage things as much > as you like. > > Making it easy to develop codenode is an important design feature we are > striving to fulfill. The major pieces of the system are becoming > sufficiently modularized such that working on a specific component does not > require deep knowledge of the entire system. We hope this will allow people > with specific specializations to have a fun time developing features either > independently, or with some counterpart collaborator who might have a > complementary expertise. > > As a project, codenode is finding a balance between providing a solid base > design for long term viability/extendability, and writing useful features > that people care about and need NOW! With this milestone, the focus of our > efforts will noticeably shift back to fulling feature requests, fixing bugs, > and sharing/proposing our own feature ideas. > > A few quick mentions of features: > General plotting capability for plain Python that is compatible with Sage. > Sage version of notebook style and key bindings. > Collaborative running notebooks, portable notebook formats, etc. > Uploading code and data for use in a notebook. > Engines for other languages. > > Looking forward to feedback! > > Thanks, > Dorian and Alex --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: finding arclength around a circle hangs maxima
to me, this looks like a strong encouragement to provide sage 4.1.3 with a couple of bugfixes (also considering something that could arise from the new notebook) anytime very soon: I don't think it is a good idea to have a release with such a serious bug, out for too long... the problem is that I wouldn't like to switch back to an old maxima, so we should at least wait for them fixing it... maybe we can help on that regards Maurizio On 16 Ott, 22:55, "ma...@mendelu.cz" wrote: > On 16 říj, 22:44, "ma...@mendelu.cz" wrote:> I am. I will > write there. > > it ishttp://thread.gmane.org/gmane.comp.mathematics.maxima.general/28550 > R. --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Notebook feature request
Can't we take advantage of inheritance for this issue? I don't know how far that can go, though, I'm not a programmer... Thanks Maurizio On Sep 28, 9:40 am, William Stein wrote: > On Mon, Sep 28, 2009 at 12:11 AM, Maurizio wrote: > > > First of all, thank you for the example! > > >> I'm pretty sure it is impossible to decide whether a cells output depends > >> on the > >> value of a given variable. You could get it write some of the time by > >> seeing > >> if the variable appears, but given the dynamic nature of Python it is > >> impossible to > >> decide in general. > > > What about the preparser? Can't we use it to recognize whether any > > variable belonging to the "live" list appear in the lines of the > > current cell? Then, it could just automatically append the "depend" > > attribute to the cell id. > > Sure, one could do that using the preparser. Unfortunately that > wouldn't really work because one cell can easily depend on the > variable x without the letter x explicitly appearing anywhere in the > cell. For example, suppose I define a function: > > def foo(): > print x > > in one cell, then put > > print foo() > > in another cell. The cell with "print foo()" in it depends on the > value of x, but x is not mentioned explicitly anywhere in that cell. > > > > > > >> That said, if you were allowed to tag a cell as depending, then this is > >> easy to > >> implement. I've even made an implementation of this in the current > >> notebook: > > >>http://sagenb.org/home/pub/905/ > > >> If you try that and evaluate all the cells in order, then you'll see > >> that changing a and b > >> causes all the other dependent cells to update. You can add > >> non-dependent cells and > >> they won't update. Obviously the above is a bit cumbersome, but could > >> be made smoother > >> if it gets at what you're after. > > >> William > > > After all, I'd be glad to see if any interest is shown in this > > direction, since there is a reasonable amount of work around the > > notebook now. Otherwise, thank you for the discussion :) > > > Maurizio > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Notebook feature request
First of all, thank you for the example! > > I'm pretty sure it is impossible to decide whether a cells output depends on > the > value of a given variable. You could get it write some of the time by seeing > if the variable appears, but given the dynamic nature of Python it is > impossible to > decide in general. > What about the preparser? Can't we use it to recognize whether any variable belonging to the "live" list appear in the lines of the current cell? Then, it could just automatically append the "depend" attribute to the cell id. > That said, if you were allowed to tag a cell as depending, then this is easy > to > implement. I've even made an implementation of this in the current notebook: > > http://sagenb.org/home/pub/905/ > > If you try that and evaluate all the cells in order, then you'll see > that changing a and b > causes all the other dependent cells to update. You can add > non-dependent cells and > they won't update. Obviously the above is a bit cumbersome, but could > be made smoother > if it gets at what you're after. > > William > After all, I'd be glad to see if any interest is shown in this direction, since there is a reasonable amount of work around the notebook now. Otherwise, thank you for the discussion :) Maurizio --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Notebook feature request
Hi all, let me catch this notebook refactoring to ask for something that just came to my mind. Let's assume you have any kind of design or analysis process flow, one great thing I'd like to have is the chance to define some input variables to be equal to a value that, whenever is updated, all the following calculations involving that same input variable are repeated. I'll try to explain better with a concrete example. At the beginning of the worksheet I could write in a cell something like: a,b = live_input([RR, CC]) and I get two input boxes like : a = [input box] b = [input box] These two variables, a and b, have a defined type (specified as argument of that "live_input" function), and a special attribute "live" (or whatever else you like), implying that the following cells have to be re-evaluated whenever the values of a and b are updated IF they (the cells) contain calculations anyhow referred to a or b. So, three cells later I have: c = a + b; c And whenever I update a or b, the evaluation of that cell is repeated and c gets updated accordingly. This also implies that c inherits the "live" attribute, so that any subsequent calculation involving "c" in the following cells is updated (re-evaluated) as well. In this way, you can imagine any kind of flow, whose input can be specified at the beginning of the worksheet, and you can immediately see the effects of changing some inputs, by just updating those boxes, and without having to manually evaluate the right cells. I think this is a piece of automation that should be pretty easily handable by the computer, and that could greatly improve the user experience. This kind of behaviour is the default in MathCad, which is very useful for this kind of flows. In that case, they have two ways of defining inputs: local definition, which affects only the subsequent calculations, and global definition, which affects all the calculations of the worksheet (also the one that comes before the global variable definition). I'll be glad to see your comments, I hope you can catch the usefulness of this (if any) :P Thanks, and regards Maurizio PS: feel free to ask me for many more insights, if I've not been clear enough --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: New interact sliders
Wouldn't be better if there was some sort of triangular end which points to the exact thick (when they are plotted)? Without them, the slider look a bit "approximate" or "inexact" :) On Sep 18, 6:14 am, William Stein wrote: > On Thu, Sep 17, 2009 at 8:39 PM, Pat LeSmithe wrote: > > I've attached a snapshot of the default sliders provided by the new > > jQuery UI spkg, available at > > >http://trac.sagemath.org/sage_trac/ticket/5447 > > > (An active slider is orange.) Also attached: Shots of custom sliders > > with thin and thinner handles. Which, if any, do you prefer? > > I think I personally prefer the middle one. > > William > > > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Behavior of solve
My 2 cents here: why do we keep the "numerical solve" function with a completely different name? I know that "find_root" or "roots" make sense, but wouldn't just be much better to name them "solve_numerical", or anything like putting a postfix after the word "solve"? I don't know whether this is generally a good thing to do, but I just keep finding it so easy if I do "solve[Tab]" so that ALL the functions related to solving equations are shown (both exact and numerical) cheers maurizio On Sep 17, 4:52 pm, Burcin Erocal wrote: > Hi, > > I don't use the solve() function at all. I'm probably missing the > user's point of view completely, so please take what I say below with a > grain of salt. > > Going by the "What Would Maple Do" rule, I would like solve() to remain > exact. Looking through the examples here > > http://www.maplesoft.com/support/help/view.aspx?path=examples/solve > > I couldn't see any cases where Maple switches to numeric results. > > I think it's better to return no results if the exact methods don't > work, and point the user to the numeric solver. This is fsolve [1] in > the case of Maple. Is it find_root() in Sage? > > [1]http://www.maplesoft.com/support/help/view.aspx?path=fsolve > > On Thu, 17 Sep 2009 06:30:19 -0700 (PDT) > > kcrisman wrote: > > > For a frustrated user because of precisely this issue, see > >http://groups.google.com/group/sage-support/browse_thread/thread/6407... > > . I now think we should definitely change to having to_poly_solve as > > an option, but not default, even if we miss some solutions that way, > > because it's unlikely that Maxima will be able to change its behavior > > very soon, even if they wanted to. > > In this case, I agree that we should make to_poly_solve a non-default > option. > > Thanks. > > Burcin --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: tutorial: en vs. fr versions
Hi all would you please consider updating this page http://wiki.sagemath.org/i18n or any other? I think it is very important to have a well defined and commonly accepted process to manage translations. I don't know how, but probably there should be an automatic notification somewhere if the documentation under translation has been modified by a patch. An online translation system could allow the translator to directly translate the most updated strings. I think that structured systems (like launchpad or anything else) could be a bit complex to setup, but probably provide orders of magnitude of more simplicity than the current system. Have a quick look here: https://translations.launchpad.net/ubuntu In fact, that is self-explained (in my opinion) by looking at how so many linux distribution have been mostly translated into so many languages, not necessarily with huge translation teams! For example: the number of elements of the Italian translation team of Ubuntu is just 16. Otherwise, I think that the translation process can become VERY frustrating My 2 cents Maurizio On Sep 9, 9:50 am, Burcin Erocal wrote: > On Tue, 8 Sep 2009 13:55:27 -0700 (PDT) > John H Palmieri wrote: > > > How important is it that these documents stay synchronized? If it's > > important, how should this be managed? Are there any francophones who > > would like to volunteer to make a translation whenever the English > > version is changed? > > IIRC, the process (probably not documented anywhere) was that if a patch > to the documentation repository was merged, another ticket would be > opened to update the translations accordingly. > > A quick search in trac turned up these: > > http://trac.sagemath.org/sage_trac/ticket/4318http://trac.sagemath.org/sage_trac/ticket/4319http://trac.sagemath.org/sage_trac/ticket/5337 > > BTW, it seems that #4318 and #5337 should be closed. > > Cheers, > Burcin --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Can I define the derivative of un unkown function
Why don't we close this ticket?
http://trac.sagemath.org/sage_trac/ticket/4566
There seems to be already a quite reasonable explanation to do this in
its comments
Maurizio
On 4 Set, 15:34, Burcin Erocal wrote:
> Hi Jason and anybody interested in symbolics in Sage,
>
> On Fri, 04 Sep 2009 07:33:12 -0500
>
>
>
> Jason Grout wrote:
>
> > Golam Mortuza Hossain wrote:
>
> > > On Sep 3, 10:52 am, Nicolas wrote:
> > >> I am trying to do the following thing but I am not sure whether
> > >> this is possible in sage (though I think it is in Mathematica)
>
> > >> Let's say I define a symbolic function
>
> > >> sage: f=function('f',x)
>
> > >> I would like to issue some command to "tell" sage what the
> > >> derivative of f is (for instance : g) so that the command
>
> > >> sage: diff(f)
>
> > >> would yield g
>
> > > Yes, its possible also in Sage. I am giving you an example that you
> > > can adapt for your need. (if you have have a function of multiple
> > > arguments then you should read diff_param keywords. For example,
> > > try heaviside?? in sage prompt to see how to read diff_param)
>
> > >
> > > sage: g = function('g')
> > > sage: def f_deriv(*args, **kwds):
> > > : return g(*args)
> > > :
> > > sage: f = function('f', derivative_func=f_deriv)
>
> > Where is this documented? I see some examples (of this and lots of
> > other keywords) under:
>
> > sage.symbolic.function.SFunction??
>
> > But I don't think most users would use sage_search or grep to find it
> > like I had to resort to after guessing a bunch of places the
> > documentation might be...
>
> > It looks like there are quite a lot of very interesting and useful
> > arguments to function. I had no idea these existed!
>
> This is some of the new functionality that came with the GiNaC wrapper.
> It was one of the first things I wrapped, and in the rush for the
> switch over from maxima, it still remains in its raw state.
>
> The interface to define new functions needs more care and polish. ATM,
> you define a class with methods _eval_, _evalf_, _derivative_, etc. and
> your function ends up being an instance of this class. I find this
> rather confusing and would appreciate any suggestions on other design
> options.
>
> There are still lots of rough edges in the new symbolics code. I don't
> have time to fix all these problems or write documentation. Though, I
> will do my best to answer questions and explain any tricky parts of the
> new symbolics to anybody interested, and put in the work to make the
> required changes (if any) at the c++ level in pynac.
>
> So if you're interested in getting the symbolics up to snuff, please
> take the plunge and look at the new symbolics code in sage/symbolic/.
>
> There are lot's of symbolics bugs on trac:
>
> http://is.gd/2SqFy[symbolics]http://is.gd/2SqMs[calculus]
>
> I can help fix the ones related to new symbolics, #6220 looks like a
> good start for example.
>
> If there is interest we can even hold a symbolics bug day where we meet
> on IRC and work on some of these.
>
> Cheers,
> Burcin
>
> P.S. Many thanks to Karl-Dieter and Golam for the patches waiting for
> review on trac. I'll try to do the reviews this weekend if no one gets
> there first.
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[sage-devel] Re: Unique variable names and their domains
Hi all
> > Consider the following situation
> > -
> > sage: xc = var('x')
> > sage: xr = var('x', domain='real')
> > sage: xc
> > x
> > sage: xr
> > x
> > sage x
> > x
> > -
I beg your pardon for asking silly questions... would you please
explain which is the reason for having different variables with the
same name... and even more, with different domains?
I could be wrong but this looks me more like a confusing thing, rather
than a feature... am I wrong? Why don't simply remove the chance to
have this, and in case the variable is redefined with the same name,
just delete it and define it again?
If not, could you please make an example of usefulness of this? Thanks
a lot!
On 4 Set, 20:48, William Stein wrote:
> 2009/9/4 Golam Mortuza Hossain :
>
>
>
> > Hi,
>
> > I am working on a patch that exposes few more properties
> > of GiNaC symbols in Sage. This will allow users to specify
> > their domains as well as custom latex_names.
>
> > Using Stan's example, it would be possible to do
> > ---
> > sui = var('sui', domain='real', latex_name="\\color{red}\\s_{u,i}")
> > ---
>
> Feature request -- can you make it so the *docstring* for the variable
> can be specified? I will have to do this soon anyways if you don't,
> since it is needed for the units package.
>
> E.g.,
>
> meter = var('meter', docstring="A meter is...", latex_name="m")
>
By the way, which is the status of the units package? Is the code
somewhere on the net? I'm quite curious! :)
Regards
Maurizio
>
>
> > However, there are some issues that needs to be discussed.
> > It seem that in GiNaC, its not possible to update the domain
> > of an already defined variable. On the hand one can have
> > different variables with same name (but different serial).
> > Thus, we need to move pynac symbol directory within Sage to allow
> > flexible usage but still keep unique variable names.
>
> > Consider the following situation
> > -
> > sage: xc = var('x')
> > sage: xr = var('x', domain='real')
> > sage: xc
> > x
> > sage: xr
> > x
> > sage x
> > x
> > -
>
> > Here we have two choices
>
> > (1)
> > -
> > sage xr is xc
> > True
> > sage: xr - xc
> > 0
> > -
>
> > (2)
> > ---
> > sage: xr is xc
> > False
> > sage: xr - xc
> > x - x
> > ---
>
> > Now my question is whether we should allow (2) or (1) ?
>
> I don't know. I'm curious -- what does Maxima do? Note that if
> Maxima can't do this, i.e. ,have one variable name with two domains,
> it will make using Maxima for anything more complicated, though not
> impossible, since we just name mangle the variable when moving it back
> and forth to Maxima.
>
> William
>
>
>
> > See also Burcin's this mail for related discussion
>
> >http://groups.google.com/group/pynac-devel/browse_thread/thread/76868...
>
> > Cheers,
> > Golam
>
> --
> William Stein
> Associate Professor of Mathematics
> University of Washingtonhttp://wstein.org
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[sage-devel] Re: 10 myths about GUI design
thanks guys :) it was just an issue with missing environmental variables like SAGE_ROOT I think, in the .emacs file. now I hardcoded the directory where SAGE is, and I'm (slowly) going to try sage-mode thanks everybody! maurizio On 31 Ago, 10:51, Pierre wrote: > maurizio, you should perhaps get in touch with Nick Alexander about > your emacs issues. The instructions you pointed at are the ones which > worked for me straight away (on Aquamacs, but any recent emacs should > do). > > what exactly is the matter ? i'll try and help. > > On Aug 30, 7:22 pm, Maurizio wrote: > > > I agree! > > > In fact, learning sage-mode has been the reason for me to start > > learning emacs. > > > The problem is that I've never used emacs and I don't really have so > > much time to spend on setting it up, and moreover, I couldn't find so > > many information about sage-mode. Apart from this wiki > > page:http://wiki.sagemath.org/sage-mode > > > For example, setting up my .emacs file didn't work so well :P I wonder > > whether some deeper installation and usage instructions are available! > > > I couldn't find anything else. Am I supposed to? I think that I > > should, since this looks very promising to me (will I be able to look > > at typeset output as well?) > > > Anyway, if that's so useful (as I hope) it looks reasonable to me to > > make this more accessible to other people, or at least more > > advertised! :) > > > Thanks and regards > > > Maurizio > > > On 30 Ago, 12:32, Pierre wrote: > > > > Maurizio, you should try emacs with sage-mode. It's exactly what you > > > (and I) want. > > > > Pierre > > > > On Aug 29, 8:57 pm, William Stein wrote: > > > > > On Sat, Aug 29, 2009 at 11:14 AM, Maurizio > > > > wrote: > > > > > > On 29 Ago, 19:21, William Stein wrote: > > > > > > On Fri, Aug 28, 2009 at 4:30 AM, Maurizio > > > > > > > > > > >wrote: > > > > > > > > Hi! > > > > > > > I have a question. > > > > > > > Would you please consider adding a feature in the notebook, if you > > > > > > > happen to work on this? > > > > > > > > My desire would be to have the chance to choose a slightly > > > > > > > different > > > > > > > type of worksheet: a "single cell"-like mode, that I intend this > > > > > > > way: > > > > > > > - one single cell to insert code, possibly with code completion, > > > > > > > code > > > > > > > coloring, and indentation management (I'm wondering whether > > > > > > > having a > > > > > > > single cell could make adding more features easier, in the way > > > > > > > that it > > > > > > > doesn't make everything too slow); > > > > > > > - one single output cell, possibly in a console-like mode (so that > > > > > > > it's also possible to try single line of code immediately); > > > > > > > Might this look a bit like this: > > > > > > >http://magma.maths.usyd.edu.au/calc/ > > > > > > > but with tab completion, etc. > > > > > > Not bad... :) > > > > > > > > - the fastest possible way to switch from one to the other: if you > > > > > > > want to do this now, you have to move back and forth in the page, > > > > > > > and > > > > > > > it's very easy to lose the point you were looking at; there are > > > > > > > hundreds of ways to do this. > > > > > > > > Better than hundreds of words, please ask somebody experienced > > > > > > > with > > > > > > > MatLab to show you the so many ways it's possible to dispose the > > > > > > > editor and the command line while working. I have often found > > > > > > > useful > > > > > > > to switch from one to another while doing different tasks. > > > > > > > Or, do you want something like Matlab has, which as far as I can > > > > > > tell is > > > > > > just a very old fashioned command line with a very intense history? > > > > > > What I mean is that the chance to access at the same time an history > > > > > powered command line, and a powerful editor (with code completion, > > > > > tabs, colors, etc.., which looks pretty standard - to not say minimal > > > > > - in these modern times) looks pretty comfortable to me, but I'll be > > > > > happy to listen to other comments. > > > > > > I've already heard talking about BeSpin (https://bespin.mozilla.com/ > > > > > ) in this list, right? Can't we have something similar? :) > > > > > > Thanks and regards > > > > > Now I understand. Thanks. Something like BeSpin in Sage could be very > > > > nice. > > > > > William > > --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: 10 myths about GUI design
I agree! In fact, learning sage-mode has been the reason for me to start learning emacs. The problem is that I've never used emacs and I don't really have so much time to spend on setting it up, and moreover, I couldn't find so many information about sage-mode. Apart from this wiki page: http://wiki.sagemath.org/sage-mode For example, setting up my .emacs file didn't work so well :P I wonder whether some deeper installation and usage instructions are available! I couldn't find anything else. Am I supposed to? I think that I should, since this looks very promising to me (will I be able to look at typeset output as well?) Anyway, if that's so useful (as I hope) it looks reasonable to me to make this more accessible to other people, or at least more advertised! :) Thanks and regards Maurizio On 30 Ago, 12:32, Pierre wrote: > Maurizio, you should try emacs with sage-mode. It's exactly what you > (and I) want. > > Pierre > > On Aug 29, 8:57 pm, William Stein wrote: > > > On Sat, Aug 29, 2009 at 11:14 AM, Maurizio > > wrote: > > > > On 29 Ago, 19:21, William Stein wrote: > > > > On Fri, Aug 28, 2009 at 4:30 AM, Maurizio > > >wrote: > > > > > > Hi! > > > > > I have a question. > > > > > Would you please consider adding a feature in the notebook, if you > > > > > happen to work on this? > > > > > > My desire would be to have the chance to choose a slightly different > > > > > type of worksheet: a "single cell"-like mode, that I intend this way: > > > > > - one single cell to insert code, possibly with code completion, code > > > > > coloring, and indentation management (I'm wondering whether having a > > > > > single cell could make adding more features easier, in the way that it > > > > > doesn't make everything too slow); > > > > > - one single output cell, possibly in a console-like mode (so that > > > > > it's also possible to try single line of code immediately); > > > > > Might this look a bit like this: > > > > >http://magma.maths.usyd.edu.au/calc/ > > > > > but with tab completion, etc. > > > > Not bad... :) > > > > > > - the fastest possible way to switch from one to the other: if you > > > > > want to do this now, you have to move back and forth in the page, and > > > > > it's very easy to lose the point you were looking at; there are > > > > > hundreds of ways to do this. > > > > > > Better than hundreds of words, please ask somebody experienced with > > > > > MatLab to show you the so many ways it's possible to dispose the > > > > > editor and the command line while working. I have often found useful > > > > > to switch from one to another while doing different tasks. > > > > > Or, do you want something like Matlab has, which as far as I can tell is > > > > just a very old fashioned command line with a very intense history? > > > > What I mean is that the chance to access at the same time an history > > > powered command line, and a powerful editor (with code completion, > > > tabs, colors, etc.., which looks pretty standard - to not say minimal > > > - in these modern times) looks pretty comfortable to me, but I'll be > > > happy to listen to other comments. > > > > I've already heard talking about BeSpin (https://bespin.mozilla.com/ > > > ) in this list, right? Can't we have something similar? :) > > > > Thanks and regards > > > Now I understand. Thanks. Something like BeSpin in Sage could be very > > nice. > > > William > > --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: 10 myths about GUI design
On 29 Ago, 19:21, William Stein wrote: > On Fri, Aug 28, 2009 at 4:30 AM, Maurizio wrote: > > > > > Hi! > > I have a question. > > Would you please consider adding a feature in the notebook, if you > > happen to work on this? > > > My desire would be to have the chance to choose a slightly different > > type of worksheet: a "single cell"-like mode, that I intend this way: > > - one single cell to insert code, possibly with code completion, code > > coloring, and indentation management (I'm wondering whether having a > > single cell could make adding more features easier, in the way that it > > doesn't make everything too slow); > > - one single output cell, possibly in a console-like mode (so that > > it's also possible to try single line of code immediately); > > Might this look a bit like this: > > http://magma.maths.usyd.edu.au/calc/ > > but with tab completion, etc. > Not bad... :) > > > > - the fastest possible way to switch from one to the other: if you > > want to do this now, you have to move back and forth in the page, and > > it's very easy to lose the point you were looking at; there are > > hundreds of ways to do this. > > > Better than hundreds of words, please ask somebody experienced with > > MatLab to show you the so many ways it's possible to dispose the > > editor and the command line while working. I have often found useful > > to switch from one to another while doing different tasks. > > Or, do you want something like Matlab has, which as far as I can tell is > just a very old fashioned command line with a very intense history? > > > What I mean is that the chance to access at the same time an history powered command line, and a powerful editor (with code completion, tabs, colors, etc.., which looks pretty standard - to not say minimal - in these modern times) looks pretty comfortable to me, but I'll be happy to listen to other comments. I've already heard talking about BeSpin ( https://bespin.mozilla.com/ ) in this list, right? Can't we have something similar? :) Thanks and regards Maurizio > > > > I know it's not said that you find this useful, but if that doesn't > > require too much work (as I hope), I think this could help a lot > > people coming from MatLab. > > > Thanks > > > Maurizio > > > On 28 Ago, 00:38, William Stein wrote: > > > On Thu, Aug 27, 2009 at 1:39 PM, Minh Nguyen > > wrote: > > > > > Hi folks, > > > > > The Sage notebook is about to get an overhaul in the next few months. > > > > Some areas that might need changes are the user interface, the API, > > > > scalability, and performance. If there is any plan to do some cosmetic > > > > facelift to the user interface, one might find the following blog post > > > > helpful: > > > > > Keith Lang "Top 10 UX Myths" > > > >http://carsonified.com/blog/design/top-10-ux-myths/ > > > > I don't _plan_ to do any UI redesign, but I would be happy to consider > > > doing UI reimplementation if somebody could precisely specify what > > > changes need to be made. I iplemented the current notebook UI but I > > > did not design -- I literally just copied the Google Docs UI from 2 > > > years ago. Note that Google Docs now looks different from the > > > notebook because they went through a redesign. > > > > William > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: 10 myths about GUI design
Hi! I have a question. Would you please consider adding a feature in the notebook, if you happen to work on this? My desire would be to have the chance to choose a slightly different type of worksheet: a "single cell"-like mode, that I intend this way: - one single cell to insert code, possibly with code completion, code coloring, and indentation management (I'm wondering whether having a single cell could make adding more features easier, in the way that it doesn't make everything too slow); - one single output cell, possibly in a console-like mode (so that it's also possible to try single line of code immediately); - the fastest possible way to switch from one to the other: if you want to do this now, you have to move back and forth in the page, and it's very easy to lose the point you were looking at; there are hundreds of ways to do this. Better than hundreds of words, please ask somebody experienced with MatLab to show you the so many ways it's possible to dispose the editor and the command line while working. I have often found useful to switch from one to another while doing different tasks. I know it's not said that you find this useful, but if that doesn't require too much work (as I hope), I think this could help a lot people coming from MatLab. Thanks Maurizio On 28 Ago, 00:38, William Stein wrote: > On Thu, Aug 27, 2009 at 1:39 PM, Minh Nguyen wrote: > > > Hi folks, > > > The Sage notebook is about to get an overhaul in the next few months. > > Some areas that might need changes are the user interface, the API, > > scalability, and performance. If there is any plan to do some cosmetic > > facelift to the user interface, one might find the following blog post > > helpful: > > > Keith Lang "Top 10 UX Myths" > >http://carsonified.com/blog/design/top-10-ux-myths/ > > I don't _plan_ to do any UI redesign, but I would be happy to consider > doing UI reimplementation if somebody could precisely specify what > changes need to be made. I iplemented the current notebook UI but I > did not design -- I literally just copied the Google Docs UI from 2 > years ago. Note that Google Docs now looks different from the > notebook because they went through a redesign. > > William --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: units
Hi all, I just wanted to add that I wrote a wiki page some time ago about this topic: http://wiki.sagemath.org/Unit%20of%20Measurement It was mainly about previously existing packages, but I still think there are some valuable information there. My other comment is that, my ideal units package wouldn't require me to deal with "convert()" functions and other stuff, but would be the most transparent possible. Another feature I'd LOVE to get is the conversion to "engineering" notation (which is similar to scientific notation), when dealing with quantities associated with a unit of measurement. The "engineering" notation as I know it, basically represents each number in scientific notation, with the exponent represented by an integer multiple of +3 or -3 EXAMPLE: 0,03 A [Amperes] -> Scientific notation: 3e-2 A -> Engineering: 30e-3 A = 30 mA 43000 m [meters] -> Scientific: 4.3e4 m -> Engineering: 43e3 m = 43 km I have this built-in in my Casio calculator (I didn't mean to do advertisement, it's just to prove it's real and working) and I LOVE it :) Another comment I have is to have a look (if possible) to MathCAD, since it supports units, and has proven pretty handful in the past. I would like very much to have units supported in symbolic equations: eq1 = x^2 + 2m * x + 1 m^2 = 0 solve(eq1) -> x = -1 m :) Regards Maurizio PS: that will result very useful, I appreciate that you accept suggestions if you don't work everyday with this stuff On 12 Ago, 17:15, "Dr. David Kirkby" wrote: > William Stein wrote: > > On Wed, Aug 12, 2009 at 7:56 AM, Robert Dodier > > wrote: > >> I think it's fairly important to keep the names of things close > >> to what people would scribble on a piece of paper. > >> Unconventional capitalization and having to write out every > >> name is going to make it clumsy to use. > > > I disagree. I've learned many times over that in math software meant > > for a large target audience it is much better to explicitly spell out > > functions instead of abbreviating them to what people would write in a > > particular area of math. The user in a particular domain can simply > > set their own shortcuts. E.g., > > > sage: N = units.newton > > Also remember, different fields use different letters to mean the same > thing. Mathematicians use 'i' for sqrt(-1). Electrical engineers use > 'j'. Any attempt to use a small variable name like 's', 't', 'K' etc is > bound to result in confusion. > > Dave --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Is new symbolic derivative really worth the efforts?
That's great! Congratulations! maurizio On 4 Ago, 18:09, Golam Mortuza Hossain wrote: > On Tue, Aug 4, 2009 at 1:02 PM, Nick Alexander wrote: > > > Can you pattern match on it? It's really irritating to do subs/ > > pattern matching on the existing derivatives. > > Yep! In fact, that was the main reason for doing so :-). The new > "diff" derivative is really a symbolic "function". So regular pattern > matching/substitution will work without any extra effort. > > Cheers, > Golam --~--~-~--~~~---~--~~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Preparse is the problem? Sage not compute FFT
that is wonderful!! by the way, I am looking forward to see those LTI and Fourier Transform features applied to our powerful symbolic system :D Maurizio On Jul 26, 9:23 pm, Rafael Cardoso Dias Costa wrote: > The problem is solved! > > http://www.sagenb.org/home/pub/677/ > > Thanks, Jason! > Thanks, everyone! > > On Sat, Jul 25, 2009 at 10:40 PM, Jason Grout > wrote: > > > > > > > Rafael Costa wrote: > > > Why Sage not execute the python code? > > > > from scipy import * > > > from pylab import * > > > > sample_rate=1000.00 > > > t=r_[0:0.6:1/sample_rate] > > > N=len(t) > > > s=sin(2*pi*50*t)+sin(2*pi*70*t+pi/4) > > > S=fft(s) > > > f=sample_rate*r_[0:(N/2)]/N > > > n=len(f) > > > plot(f,abs(S[0:n])/N) > > > Seehttp://sagenb.org/home/pub/676/for a working version: > > > from scipy import * > > from pylab import * > > sample_rate = 1000.0 > > t = r_[0:0.6:1/sample_rate].astype(float) > > N = len(t) > > s = sin(2*pi*50*t)+sin(2*pi*70*t+pi/4) > > S = fft(s) > > f=sample_rate*r_[0:(N/2)]/N > > n=len(f) > > line(zip(f,abs(S[0:n])/N)) > > > As Minh points out, the need for the "astype" above will go away once > > the three tickets (that are up for review!) are reviewed and merged; > > hopefully in the next few days. > > > Thanks, > > > Jason > > -- > Rafael Cardoso Dias Costa > Engenheiro de Controle e Automação - UFMG > Mestrando em Engenharia Química - Controle de Processos - UFRGS > +55 51 8541-0926 :: Porto Alegre - RS > +55 51 8430-1421 :: Porto Alegre - RS > +55 31 9165-5488 :: Belo Horizonte - MG > +55 31 3466-0146 :: Residência em Belo Horizonte - MG --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Circuits
Wow, my field! :) I would like to add that SAGE can open a new door to circuit analysis, thanks to its symbolic manipulation. A friend of mine adopted the techniques to solve the circuits defined by a netlist like in SPICE. If you adopt that same technique in SAGE, you are allowed to define one or more terms symbolically, so you can study transfer functions and stuff like that by simply drawing the circuit in any SPICE program. Regarding Circuit Engine, I have to say that it looks pretty simple and slightly lacking interesting features, but I don't want to be rude toward such an appreciable initiative. I hope that it relies on well spread standards like SPICE or SPECTRE netlist Thanks for focusing on this as well :) Maurizio On Jul 26, 10:24 pm, David Joyner wrote: > This seems interesting. > > I teach circuits and networks every semester as an application of > ODEs/systems of ODEs. The EMF is not necessarily constant > and occasionally we might have a variable term (eg, a variable capacitor). > Questions: > > 1. Does his program allow non-constant terms and symbolic terms? > > 2. How does it draw circuits? (I use Dia now for cicuits in lecture > notes and exams > but his circuits look nicer, IMHO.) > > 3. Are there any examples of an output (eg, given a parallel circuit > with a capacitor, EMF, resistors and inductors, can it find the charge on the > capacitor as a function of t)? > > On Sun, Jul 26, 2009 at 2:07 PM, William Stein wrote: > > > Hi Sage-Devel (in particular, people who know about electrical circuits), > > > I just happen to be meeting with an undergrad tomorrow at Univ. of > > Washington about him possibly working with me, and he mentioned that > > he wrote the following himself > > http://www.circuitengine.com/ > > > He also said he may be interested in GPL'ing it, possibly getting > > something based on it into Sage (http://sagemath.org), etc. > > > So, if there are any electrical engineers out there, what do you think? > > > I think it's a Java program, so it could be easily embedded in the > > Sage notebook. > > > As a personal note, I was taking an electrical engineering course as a > > CS undergraduate and the mathematics in that course is what really > > pushed me over to become a mathematician (and change majors). > > > William > > > -- > > William Stein > > Associate Professor of Mathematics > > University of Washington > >http://wstein.org --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Is new symbolic derivative really worth the efforts?
t;integration" > and others? > > Cheers, > Golam At the very end, my personal opinion is that the community should plan the work on derivatives AND integrals at the same time, otherwise it does not make sense to stick with some derivatives we are not going to support in the long term (integrals are going to take a lot of time probably). My 2 cents best regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Real domain for symbolic variables
I think it has been a good idea to create such a new google groups for Pynac, but at the moment it is just empty! :) It would probably help focusing on some topics related to symbolics, and be more suitable for communication of new stuff/features to the community, without necessarily bothering everybody. Regards Maurizio On Jul 18, 2:57 pm, Minh Nguyen wrote: > Hi Golam, > > On Sat, Jul 18, 2009 at 10:49 PM, Golam Mortuza > > Hossain wrote: > > > > > I could implement above rather easily by exposing underlying Ginac > > feature. However, I am not sure how to submit patches for pynac/ginac > > as its not under "devel/sage". > > The Pynac website is > > http://pynac.sagemath.org/ > > You can send an email to the pynac-devel group for all matters > relating to the development of Pynac: > > pynac-de...@googlegroups.com > > -- > Regards > Minh Van Nguyen --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Naming Conventions for Dirac Delta, Heaviside Theta and Unit Step
I agree. We could do something like plotting all the deltas with a stem plot and then superimposing the rest of the plot Maurizio On 24 Giu, 04:21, David Roe wrote: > One way would be to have a vertical ray that doesn't change the scaling of > the rest of the graph (just goes to the top of the viewing window). Not > precisely accurate, but better than nothing. > David > > On Tue, Jun 23, 2009 at 6:57 PM, Tim Lahey wrote: > > > On Jun 23, 2009, at 5:46 PM, Maurizio wrote: > > > > As a clarification of what I was talking about, see this: > > > >http://mathworld.wolfram.com/ImpulsePair.html > > > > Regards > > > > Maurizio > > > How are they supposed to be plotted? Along with other impulses, > > it would be fine, but next to any normal function, the impulses > > would skew the scale and make all the other functions disappear. > > > Cheers, > > > Tim. > > > --- > > Tim Lahey > > PhD Candidate, Systems Design Engineering > > University of Waterloo > >http://www.linkedin.com/in/timlahey --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Naming Conventions for Dirac Delta, Heaviside Theta and Unit Step
As a clarification of what I was talking about, see this: http://mathworld.wolfram.com/ImpulsePair.html Regards Maurizio On 23 Giu, 23:45, Maurizio wrote: > Many kudos for this! > > Honestly, I don't actually know whether it means that much, but at > this point I think that it could be useful for us to follow > Mathematica in defining two different functions: Heaviside which is > undefined in 0 and that is defined as the function whose derivative is > the Dirac Delta ( > seehttp://functions.wolfram.com/GeneralizedFunctions/HeavisideTheta/02/ > ) and UnitStep, which is the piecewise version of this function, so > it's numerically defined everywhere. It would be great if one could > possibly change the desired value in 0. > > I think it doesn't hurt now to carry on both, because it shouldn't be > that difficult to merge them in future if we don't see any usefulness > in having them separated. > > I can see that Maple use Heaviside undefined in 0, and then let the > user the chance to convert it to a piecewise function if desired. This > looks a bit unfriendly to me, and doesn't bring any real advantage. > > By the way, how do we represent Dirac Delta? I know that it's not > defined in 0, but I want to point out an example. Please, remember > that the Fourier transform of any periodic function (although the use > of the transform is not proper in case of periodic functions, I know) > is formed by the summation of Dirac Deltas at different location in > the frequency spectrum, and I would love to have a graphical > representation of the spectrum of a signal. So, do you think we can > find a convenient way of plotting delta? I don't know much of them, > but I'm sure there are many similar physical problems, that would take > advantage of plotting deltas. > > Thanks again > > Maurizio > > On 23 Giu, 19:02, Golam Mortuza Hossain wrote: > > > Thanks David, Tim, Burcin! > > > Correct me if I have missed your points. With your suggestions > > here is the new conventions for Heaviside and unit step > > > (2) Heaviside: > > > (a) represented as: "heaviside" > > (b) latex name : "\theta" > > (c) heaviside(0): will return symbolic expression "heaviside(0)" > > > (3) unit_step = heaviside (Just an alias) > > > >> Will, for example, sin(t)*unit_step(t) be defined? > > >> If so, will you provide a plotting and _latex_ method for it? > > > > I really hope so. > > > These functions are sub-class of PrimitiveFunctions of new > > symbolics. So many methods are predefined. For example, > > I didn't write any code for plotting but it works. > > > Here is a screenshot from my Sage notebook. > > >http://www.math.unb.ca/~ghossain/sage-generalized-functions.png > > > Hopefully, it answers some of your questions. I am still working > > on integration algorithm. > > > Cheers, > > Golam --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Naming Conventions for Dirac Delta, Heaviside Theta and Unit Step
Many kudos for this! Honestly, I don't actually know whether it means that much, but at this point I think that it could be useful for us to follow Mathematica in defining two different functions: Heaviside which is undefined in 0 and that is defined as the function whose derivative is the Dirac Delta ( see http://functions.wolfram.com/GeneralizedFunctions/HeavisideTheta/02/ ) and UnitStep, which is the piecewise version of this function, so it's numerically defined everywhere. It would be great if one could possibly change the desired value in 0. I think it doesn't hurt now to carry on both, because it shouldn't be that difficult to merge them in future if we don't see any usefulness in having them separated. I can see that Maple use Heaviside undefined in 0, and then let the user the chance to convert it to a piecewise function if desired. This looks a bit unfriendly to me, and doesn't bring any real advantage. By the way, how do we represent Dirac Delta? I know that it's not defined in 0, but I want to point out an example. Please, remember that the Fourier transform of any periodic function (although the use of the transform is not proper in case of periodic functions, I know) is formed by the summation of Dirac Deltas at different location in the frequency spectrum, and I would love to have a graphical representation of the spectrum of a signal. So, do you think we can find a convenient way of plotting delta? I don't know much of them, but I'm sure there are many similar physical problems, that would take advantage of plotting deltas. Thanks again Maurizio On 23 Giu, 19:02, Golam Mortuza Hossain wrote: > Thanks David, Tim, Burcin! > > Correct me if I have missed your points. With your suggestions > here is the new conventions for Heaviside and unit step > > (2) Heaviside: > > (a) represented as: "heaviside" > (b) latex name : "\theta" > (c) heaviside(0): will return symbolic expression "heaviside(0)" > > (3) unit_step = heaviside (Just an alias) > > >> Will, for example, sin(t)*unit_step(t) be defined? > >> If so, will you provide a plotting and _latex_ method for it? > > > I really hope so. > > These functions are sub-class of PrimitiveFunctions of new > symbolics. So many methods are predefined. For example, > I didn't write any code for plotting but it works. > > Here is a screenshot from my Sage notebook. > > http://www.math.unb.ca/~ghossain/sage-generalized-functions.png > > Hopefully, it answers some of your questions. I am still working > on integration algorithm. > > Cheers, > Golam --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Dirac delta in new symbolics
Glad to see this issue coming out again :) I just would like to point out that Burcin recently highlighted ( http://groups.google.com/group/sage-devel/msg/368c6c89935b85ad ) that there was a discussion ongoing with Mike Hansen about changing the design of SFunction. I am wondering if that's still pending, or it has been done, so that some documentation to new design could be helpful, given that Dirac delta implementation should rely on that. Thanks Maurizio On 17 Giu, 13:56, Burcin Erocal wrote: > Hi Golam, > > On Wed, 17 Jun 2009 07:38:16 -0300 > Golam Mortuza Hossain wrote: > > > We had discussions earlier on having Dirac delta distribution > > included in Sage. Now that we have switched to new symbolics, > > let me bring this issue once again. > > > Is anyone working in implementing Dirac delta in new symbolics? > > > While working with my own Physics problems in Sage, I often find > > myself constrained for not having Dirac delta. If no one is working > > on it then I will implement at least some properties that I need. > > If someone is already working on it then I will be happy to > > collaborate. > > I don't know anyone working on this atm. You could do this as part of > #2452 on trac. The example code I wrote for Maurizio is here: > > http://sage.math.washington.edu/home/burcin/pynac/dirac.py > > You probably need to put those evalf functions in the appropriate > PrimitiveFunction class, and add other properties as desired. > > Thanks for volunteering! > > Cheers, > Burcin --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Feature Request: element-wise multiplication of matrices
+1 for including this function... I had made the same one, but mine is
actually 5 times slower than the one proposed in trac 6245 :P
Is it possible to not name it "hadamard_product"? Coming from MatLab,
I've used it hundreds of time, but I would have never recognized that
"hadamard_product" could be the name associated to it.
If possible, in case of a new function, I would call it
"mul_something" so that anybody looking for some sort of
multiplication could enter: "mul[Tab]" and get something like:
"mul_elementwise", and immediately recognize the meaning :) In my
opinion, guessing the first letters of the operation (multiplication)
is much easier than guessing those of the adjective (elementwise?
hadamard?...).
OffTopic: Just for the records, for the same reason I would like to
find an alias of the "find_root" function, with the name
"solve_numerical" or something like that, so that when I do "sol[Tab]"
I get all the functions related to solving an equation, whatever the
domain.
Regards
Maurizio
On 15 Giu, 17:08, Jason Grout wrote:
> paramaniac wrote:
> > Dear Sage Developers,
>
> > It would be very nice if Sage supported the element-wise
> > multiplication of matrices like the .* operator in Octave/Matlab.
>
> I was about to point out the recent thread about this, but then realized
> it was you that started that thread and acknowledged the response. Are
> you saying that you would like to see the code mentioned in that thread
> (http://groups.google.com/group/sage-support/browse_thread/thread/011a...)
> incorporated into Sage as a function, maybe as P.hadamard_product() or
> something?
>
> Jason
>
> > EXAMPLE:
>
> > sigma, tau, beta = var('sigma tau beta')
> > A = matrix([[-1/tau, sigma/tau],[sigma/tau, -1/tau]])
> > B = matrix([[beta/tau, 0],[0, beta/tau]])
> > C = matrix([[1,0],[0,1]])
> > D = matrix([[0,0],[0,0]])
> > I = identity_matrix(2)
> > s, t = var('s t')
> > P = C*(s*I-A)^(-1)*B+D
> > P = P.simplify_rational()
>
> > RGA = P .* P.inverse().transpose()
>
> > Regards,
> > Lukas
>
>
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[sage-devel] Re: Wiki translation?
Hi all, as stated in the i18n Italian page, the current reference for the documentation can be considered this repository of .rst files: http://sage.math.washington.edu/home/mhansen/doc-sphinx/tutorial/ Is this information updated? In that case, I'll start providing the translated .rst files. Is there any guideline for Sphinx syntax? If the current documentation is not there, which is the most updated source? Moreover, how are the available translations made public? I don't see any advertisement. Thanks Regards Maurizio On 22 Mag, 09:10, Franco Saliola wrote: > On Thu, May 21, 2009 at 11:00 PM, Maurizio wrote: > > > Hi all, > > > For some strange reason, I fell into the SAGE-intro-Italianwiki page. > > I amItalian, and I can see that translation has been done with an > > automatic translator (something like babelfish or google translate), > > and looks a bit embarrassing :) > > > I am willing to give my contribute providing a "human"Italian > > translation to that intro page. Are you willing to get some more pages > > translated as well? I know this is low priority, yet I feel this could > > represent a small payback to your great work. > > > So, if you like, let me know how to do that (please, consider that I > > have no experience with wiki page editing, although I have no fear to > > learn), and which are the sources you consider the most important, and > > would like to see translated. I think that an important point is to > > focus on the pages you care the most, and probably the introduction to > > all the functionalities, since this could help people to fall into > > SAGE by looking for something else in google :) > > > I know this looks pretty useless, since nowadays everybody should > > speak English, yet I know universities are still full of people not > > necessarily fluent in English. > > Ciao Maurizio, > > Please also take a look at this page, > > http://wiki.sagemath.org/i18n/Italian > > Fixing the SAGE-intro-Italianis one of the things on their todo list. So > is translating the tutorial. > > Beware: there has not been much work on theItaliantranslation for about 6 > months, and so the files listed on the page are from an old version of the > tutorial (although I don't know how much the tutorial has actually changed). > It would be better to work with the documentation that is included with the > latest version of the Sage. > > After the translation, the documentation can then be included with Sage, as > it currently includes the French documentation (see > $SAGE_ROOT/devel/sage/doc/fr/tutorial). > > Thanks for this! > Franco > > -- --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Wiki translation?
Hi all, For some strange reason, I fell into the SAGE-intro-Italian wiki page. I am Italian, and I can see that translation has been done with an automatic translator (something like babelfish or google translate), and looks a bit embarrassing :) I am willing to give my contribute providing a "human" Italian translation to that intro page. Are you willing to get some more pages translated as well? I know this is low priority, yet I feel this could represent a small payback to your great work. So, if you like, let me know how to do that (please, consider that I have no experience with wiki page editing, although I have no fear to learn), and which are the sources you consider the most important, and would like to see translated. I think that an important point is to focus on the pages you care the most, and probably the introduction to all the functionalities, since this could help people to fall into SAGE by looking for something else in google :) I know this looks pretty useless, since nowadays everybody should speak English, yet I know universities are still full of people not necessarily fluent in English. Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Functional derivative in Sage using pynac
Hi,
I had previously been interested in implementing delta dirac function
in pynac, especially for Laplace transform, so maybe I can give you a
couple of references.
First of all, the (quite long) thread about this in the sage-devel
group:
http://groups.google.com/group/sage-devel/browse_frm/thread/91289956e4db80c6/368c6c89935b85ad?lnk=gst&q=delta+dirac+pynac#368c6c89935b85ad
In the first response, Burcin had given a link to his (very basic)
draft of the dirac_delta function that he sent me a couple of weeks
ago.
Moreover, I think another interesting thread is the one on the SymPy
bugtracker:
http://code.google.com/p/sympy/issues/detail?id=672
At the end of this thread, they have the DiracDelta implemented, so
you can actually read some python code implementing dirac delta,
although based on SymPy.
I can't give references about Maxima, because I'm not able to
understand LISP, so that would have been useless to me.
My final comment is that, I have understood that I should better wait
for SAGE 4.0 to come back with these kind of issues, because that
would be the first release (if I got it right) with Pynac enabled
(maybe by default?), and so after that we can start working on
building something on top of it. I am not even sure if something in
Pynac engine is not going under some rewriting or development. But I
think that 4.0 is coming soon!
I would be glad to hear your impressions and to be updated on your
work :)
Regards
Maurizio
On 2 Mag, 20:53, Golam Mortuza Hossain wrote:
> Hi,
>
> On Sun, Apr 26, 2009 at 7:43 PM, Tim Lahey wrote:
> > I do it from a mathematical perspective. The code to do the variation
> > itself is
>
> Thanks Tim. I played around further with current Sage to see what
> stuffs need to be improved in implementing functional derivative in Sage.
> I followed the mathematical definition that you did in maple. In Physics,
> one takes the test-function to be Dirac delta (that's the only difference).
>
> I tried with the following simple implementation
> -
> def fdiff(L, q):
> """
> Functional Derivative
> """
> var('epsilon');
> f(t) = function('dirac_delta',t) # Test function
>
> return diff(L.substitute(q=q+epsilon*f(t)), epsilon).substitute(epsilon=0)
>
> # Example usage:
>
> # Time and Position
> var('t'); q(t) = function('q',t)
>
> # Lagrangian for Simple Pendulum
> L = (diff(q(t),t))^2/2 - q(t)^2/2
>
> # Action
> S = integrate(L, t)
>
> # Euler-Lagrange equation directly follows from variation of action
> fdiff(S,q)
> --
>
> In fact, above 'works' in current sage but only after misusing
> current "substitute" method.
>
> To implement proper functional derivative in current Sage,
> following stuffs need some work
>
> (1) Improved "substitute()":
>
> Currently, "substitute" works, if keyword is a symbolic variable.
> It doesn't seem to work when keyword is a symbolic function. Does
> anyone know whether there are other ways in Sage to substitute
> a symbolic function by a symbolic expression?
>
> (2) dirac_delta(x):
>
> I am planning to use Sage to compute Poisson brackets where
> I need functional derivative (with Dirac delta as test-function).
> Maxima seems to have implemented Dirac delta (for Laplace
> transform). Does anyone working in implementing Dirac delta
> in Sage? (or in pynac?)
>
> I am planning to start working on the above two. However, I
> will prefer to avoid any effort duplication.
>
> Thanks,
> Golam
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[sage-devel] Re: sage and symbolic software design
Hello > Sure, this is true. It is certainly true of computer algebra systems > where (for example) relative large amounts of effort are devoted to > parts of systems which are pretty much doomed to be of almost no use > except demonstrations. Simple example: almost no one other than > freshman calculus students are interested in doing symbolic indefinite > integrals, and even they are not interested in the decision procedure > for integration in finite terms in terms of elementary functions. The > applications are for definite integrals, which have for many many I tend to disagree on this. In my opinion, you tend to consider data analysis the only "application", but design and synthesis are another very important area. There, data crunching is far less important, and symbolic manipulations are much more important, to understand the design trade offs. So, for my everyday work (as an engineer, so very application oriented) I consider symbolic management (look in this group how often I do ask for symbolic indefinite integration, symbolic laplace/fourier transforms, etc) at least as important as numerical data analysis. > There are quite a few people now improving Maxima without rewriting > it in python. There is material in the open literature that suggests > a total redesign might cure some problems. I've written some of it. > So far as I know, the Sage people are not aware of these issues. They > might even be in the parts that are not needed by current users and so > would be left out, much to the detriment of future directions of > growth. > > A reason for (doing something like rewriting Maxima in python) might > be what you suggest below, sort of. > > (e) A complete redesign of a computer algebra system with facilities > like those in Maxima, from top to bottom is long overdue. We propose > to do this. We want to use Python because, uh, because we think uh, > high school students know Python? And Lisp is bad for computer > algebra. See how hard it was to use in Maxima, Reduce, Jacal, > Axiom, ... > [Maple and Mathematica are, I think, written in C extended in some > ways]. > I would like to kindly ask you to point out the reasons for which Maxima would take advantage from a complete redesign, so that these points can be already taken as the starting points of the new CAS. I'm sure you can give a lot of good (potentially constructive) advices, and I'm sure people here are really willing to listen for them. Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] notebook issue?
Hi today I was looking for a worksheet in Trash. So found it, I opened it, and then I recognized that was the one I was looking for. To undelete it, I pressed "Discard and quit", so that I could have gone back to the trash worksheet list, to do "Undelete". I recognized the worksheet was not there anymore. By pressing "Discard and quit", it was moved to the "Active" folder. Is this desirable? I don't think so. I was actually very afraid I could have lost it, but then I just found it in Active. Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Indefinite Integration [WAS: programming: define a new function]
> We managed to get one gsoc project that does the assumptions right, so > it may happen anyways over the summer, in fact I very much hope so. > How does assumptions affect this? If that's so important, you should probably get a lot of focus on that! But consider also PDE important ;) > > We'll see. We managed to get 5 gsoc student this summer, so we are not > at all dead, if this is what you mean. :) > That's definitely a very good thing, especially in getting people involved with development... Probably the best result is not just their short term, but also the chance of some long term commitment of good people. > Besides, it will take almost a year to Sage too to release the new > symbolics (started August 2008), so I don't think we are doing that > bad. > Also in terms of developers working just on symbolics, I think sympy > has much more developers. I don't know if it's easy to extract just > patches to Sage symbolics, to compare speeds of developments, but I > would not be surprised if it turns out it's actually very comparable, > or even less people are working on Sage symbolics than on sympy. > That's a very good point. In my opinion, SAGE community is very good, and vast, and very well driven, but its focus it's actually quite far from symbolics (there's nothing bad about it), so I can see that for the time being, SymPy has some more inertia, thanks to the higher number of developers committed to symbolics (of course) rather than SAGE. At the same time, I think that SAGE can make a big step forward, once its community focuses on this task! Thanks a lot Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: programming: define a new function
thank you for clarifying this, I didn't know that sympy was already pretty well working with the new symbolics I hope this has at least given some information to the community as well! I always learn a lot from these discussions Regards Maurizio On 21 Apr, 22:58, Jason Grout wrote: > Ondrej Certik wrote: > > On Tue, Apr 21, 2009 at 1:10 PM, William Stein wrote: > >> On Tue, Apr 21, 2009 at 1:06 PM, Ondrej Certik wrote: > >>> On Mon, Apr 20, 2009 at 5:31 AM, Maurizio > >>> wrote: > >>>> Kudos to SymPy! > > >>>> I'm wondering why the python integration algorithms implemented there > >>>> aren't in the short term adopted by SAGE. > >>> They are --- you can use them from sympy inside Sage. It's my goal > >>> that all sympy features are nicely integrated in Sage. I work on this > >>> as time permits. > >> Also, in the pynac-based symbolics that Mike Hansen has been polishing > >> up for full inclusion in Sage (to replace the maxima based symbolics), > >> one can just do > > >> f.integrate(algorithm="sympy") > > >> and sage will compute the integral using sympy. He's already > >> implemented this and I've seen it work well when I tried it out. > > > Yes, that way Sage allows to call any of those libraries very easily > > in Sage and at the same time uses just one library by default, that > > currently is the best at integrating, I guess still Maxima. > > unless maxima doesn't produce an answer (i.e., returns your expression > unevaluated or throws an exception because of an assumption, etc.) Then > it could automatically try sympy. > > -Jason > > -- > Jason Grout --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Indefinite Integration [WAS: programming: define a new function]
Hi Michael, Actually, I thought that this discussion (especially people much more expert than me) has clarified the point that implementing integrals is not really just matter of a couple of months... but I would be glad to see this happen! I know there are some license issues with SymPy (not really issues, just differences probably) but I think there's no problem in taking inspiration and some pieces of code from it, right? I'm saying this, because I can see this new symbolic stuff exciting, but without the right amount of interest on it, its development will always be a little slow Regards Maurizio On Apr 21, 1:12 am, mabshoff wrote: > On Apr 20, 1:12 pm, Maurizio wrote: > > > Hi Burcin, thanks for replying! > > > > > I don't know what about those algorithms, but it seems to me that > > SymPy already implements some good heuristics, which can solve > > integrals that Mathematica can't. > > Well, there are many, many integrals that MMA can do that Sympy > cannot. So it doesn't matter that in this specific case SymPy solves > it. > > > So can we take this as a starting > > point? I see that it is certainly possible to implement everything > > from the beginning, but a bootstrapped start seems better to me in the > > short term, because this could provide the user the functionalities > > needed. This could be useful to speed up the switch to the new > > symbolic system (I think you wouldn't do that without a good > > integration engine), and once there, you got a great exposure to bug > > fixing by users. > > Well, talking about it won't make it happen :). People working on > Symbolics in Sage are well aware of Sympy and its capabilities, but it > is BSD (i.e. some people won't work on it) and abstract mathematical > capabilities aren't as well developed as in Sage and often quite a bit > slower. Pynac is building Symbolics from the ground up and it has > taken a while to get to where we are and another couple months more or > less won't make a difference at this point. > > > Thanks > > > Maurizio > > Cheers, > > Michael --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Indefinite Integration [WAS: programming: define a new function]
Hi Burcin, thanks for replying! > I agree that it's confusing, but it's not a bug. > > The command > > sage: Bs = NSR(B) > > converts the polynomial B = x^3 + x in QQ[x] to a symbolic expression, > with one numeric coefficient, namely B. > Excuse me, but I don't understand the reason for this. When does this come handful, if you can't directly translate that polynomial into a symbolic expression? > sage: Bs.coeff(x) > 0 > sage: Bs.is_constant() > True > sage: Bs.pyobject() > x^3 + x > sage: Bs.pyobject().parent() > Multivariate Polynomial Ring in x, z over Rational Field > > Since Bs is a constant w.r.t. the symbolic x, the derivative of Bs > w.r.t. the symbolic variable x is 0. > > In order to convert the polynomial to a symbolic expression, I suggest > substituting the symbolic variables in the polynomial. > > sage: B.subs(x=x) > x^3 + x > sage: t = B.subs(x=x) Is really this the correct way? Are you satisfied with this? Even if its user friendliness could be questionable, I find it rather inelegant... what do you think? I would consider switching the normal behavior, if possible. > sage: t.coeff(x) > 1 > sage: t.coeff(x^3) > 1 > sage: t.derivative(x) > 3*x^2 + 1 > > > > > A good integration algorithm probably has a couple of phases -- first > > you try some heuristics, and pattern-match against a database of known > > integrals; if those fail, then you bring out the big guns and apply > > the decision procedure. If you're interested in working on > > integration, maybe you'd rather work on the first phase? That > > probably requires more computer science and less math than the second > > phase. > > Indeed, this was what I tried to say in those comments about > integration that got Maurizio started on this track. > > There are descriptions of heuristics we can use in the maxima manual [1] > and the book by Geddes, Czapor and Labahn [2]. > > [1]http://maxima.sourceforge.net/docs/manual/en/maxima_20.html#Item_003a... > > [2]http://books.google.at/books?id=9fOUwkkRxT4C&pg=PR2&hl=en#PPA473,M1 > > It would be great if someone went through these links, and made them > more explicit/precise. As I said before, implementing these should be > within reach with the pattern matching/rewriting capabilities of pynac. > > Here is an example, pointed out to me by Clemens Raab, which maxima can > do and MMA can't: > > sage: g=log(1-x)/(polylog(2,x)^2+log(1-x)*polylog(3,x)) > sage: f = g.derivative(x) > sage: integral(f,x) > log(1 - x)/(log(1 - x)*polylog(3, x) + polylog(2, x)^2) > > Cheers, > Burcin I don't know what about those algorithms, but it seems to me that SymPy already implements some good heuristics, which can solve integrals that Mathematica can't. So can we take this as a starting point? I see that it is certainly possible to implement everything from the beginning, but a bootstrapped start seems better to me in the short term, because this could provide the user the functionalities needed. This could be useful to speed up the switch to the new symbolic system (I think you wouldn't do that without a good integration engine), and once there, you got a great exposure to bug fixing by users. Thanks Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: programming: define a new function
Kudos to SymPy! I'm wondering why the python integration algorithms implemented there aren't in the short term adopted by SAGE. At least, they are already aware of their shortcomings (ie: cannot compute the integral of log(x)/x ). I'm sure SAGE people could give big contribute to those, send patches upstream, and move forward if needed. Regards and many thanks Maurizio On Apr 20, 12:57 am, Ondrej Certik wrote: > On Sun, Apr 19, 2009 at 4:20 PM, root wrote: > > >> So we have a good start to implement the Risch algorithm in sympy already. > > > Ondrej, what result do you get for: > > > integrate(sqrt(x+log(x)),x) > > In [1]: integrate(sqrt(x+log(x)),x) > Out[1]: > ⌠ > ⎮ > ⎮ ╲╱ x + log(x) dx > ⌡ > > So we can't do it yet. > > Ondrej --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: programming: define a new function
Challenging? Just because about the problem of integration in finite
terms Hardy in 1916 stated that “there is reason to suppose that no
such method can be given” ? :)
I want to add to this discussion that I found a lot of useful
information in this thread from SymPy list:
http://groups.google.com/group/sympy/browse_frm/thread/47259e49ad1cfd13/7a98521ffb13e311?lnk=gst&q=risch#7a98521ffb13e311
I'm wondering whether it could be a good idea to add to the Pynac wiki
a link to this article from Manuel Bronstein:
http://www-sop.inria.fr/cafe/Manuel.Bronstein/publications/issac98.pdf
This seems a good reading!
Moreover, in the same thread, I read that a lot of work has been
accomplished in SymPy. I know I can sometimes sound like a broken
record (always repeating the same crap...), but I more and more see
like a great advance in taking advantage of SymPy's python code. I am
willing to go and read it, and hopefully I can catch at least a single
bit from it :P I want to point out that this (in my opinion) is just
to give pynac a fastest bootstrap, so that we can start working on
improving something already there.
Unfortunately, porting some of SymPy's code sounds more like a
Computer Science task, which is not really my field.
If I look at my first aim (Laplace and Fourier transforms...) I can
see a long way to cover, hopefully in the shortest time frame!
Regards
Maurizio
On 19 Apr, 17:10, Martin Musatov wrote:
> Aha! Quite the challenge is it not?
>
> On Sun, Apr 19, 2009 at 7:44 AM, Maurizio wrote:
>
>
>
> > Hi all
>
> > > Well, we just need a resultant algorithm that doesn't go through
> > > Singular. I'm planning to write such a thing as part of my
> > > cylindrical algebraic decomposition implementation sometime in the
> > > next few months.
>
> > > Carl
>
> > yes, I agree with that.
>
> > William, unfortunately I can't understand what the function "variety"
> > will help for. Basically, I just wanted to see if I could implement
> > the most basic algorithm for rational functions integration, and I
> > followed the link in the Pynac wiki. Probably, my mistake was to
> > introduce polynomials in this path, but that's the only place where I
> > found the "resultant()" function. Do you have any alternative
> > suggestion?
>
> > Carl, I took advantage of your suggestion, even though I assume I
> > can't still go through the whole process with the current gcd
> > capabilities in Pynac. But before than that, I'd like to point out
> > something strange I did notice, and maybe also Burcin can help with
> > that:
>
> > reset()
> > # P. = PolynomialRing(QQ)
> > # P. = GF(5)[]
> > P. = QQ[]
>
> > A = 1
> > B = x^3 + x
>
> > tores = A - z*diff(B,x)
> > res = tores.resultant(B,x); factor(res)
> > res1 = res.univariate_polynomial()
> > sol1 = res1.roots(ring = QQbar)
>
> > with this code, I get the roots over QQbar, which is useful. Then I'd
> > like to move to the symbolic field and I do this:
>
> > var('x, zs', ns = 1)
> > from sage.symbolic.ring import NSR
> > As = NSR(A)
> > Bs = NSR(B)
> > Bs
> > x^3 + x
> > Bs.diff(x)
> > 0
>
> > So, the derivative is not working. Which is the cause? It seems that
> > the "x" in Bs is not the "x" I declared, so the derivative gets 0 as a
> > result. Which is the reason?
>
> > Assuming to go on (manually for the moment), I do:
> > c1 = QQbar(sol1[0][0])
> > v1a = A - c1*(3*x^2 + 1)
> > Bs.gcd(v1a)
>
> > Traceback (click to the left for traceback)
> > ...
> > RuntimeError: gcd: arguments must be polynomials over the rationals
>
> > Traceback (most recent call last):
> > File "", line 1, in
> > File "/home/notebook/sage_notebook/worksheets/admin/4/code/135.py",
> > line 9, in
> > Bs.gcd(v1a)
> > File "/usr/local/sage/local/lib/python2.5/site-packages/
> > zope.interface-3.3.0-py2.5-linux-i686.egg/", line 1, in
>
> > File "expression.pyx", line 1624, in
> > sage.symbolic.expression.Expression.gcd (sage/symbolic/expression.cpp:
> > 8608)
> > RuntimeError: gcd: arguments must be polynomials over the rationals
>
> > My point is: even though I could get the roots in QQbar (which are
> > exact), it seems that Pynac is not happy to work with QQbar
> > quantities, the only supported seems to be QQ pure rationals.
>
> > Moreover, I don't see this being the right way to do this, because
> > (for this particular problem: integration) I don't like h
[sage-devel] Re: Embedding iframes into output cells
Nice! :) On 19 Apr, 16:42, Pat LeSmithe wrote: > In case there's interest... It's possible to embed any web page into an > output cell with a bit of client-side mischief: > > http://www.sagenb.org/home/pub/464/ > > Since this uses cell_div_output_*, the embeds won't respond to requests > to hide themselves or to delete all output. Perhaps it's better to > implement this in the server. > > This suggests a way to display long docstrings, live docs, or > non-standard docs inline, with scrollbars. --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: programming: define a new function
Hi all
> Well, we just need a resultant algorithm that doesn't go through
> Singular. I'm planning to write such a thing as part of my
> cylindrical algebraic decomposition implementation sometime in the
> next few months.
>
> Carl
yes, I agree with that.
William, unfortunately I can't understand what the function "variety"
will help for. Basically, I just wanted to see if I could implement
the most basic algorithm for rational functions integration, and I
followed the link in the Pynac wiki. Probably, my mistake was to
introduce polynomials in this path, but that's the only place where I
found the "resultant()" function. Do you have any alternative
suggestion?
Carl, I took advantage of your suggestion, even though I assume I
can't still go through the whole process with the current gcd
capabilities in Pynac. But before than that, I'd like to point out
something strange I did notice, and maybe also Burcin can help with
that:
reset()
# P. = PolynomialRing(QQ)
# P. = GF(5)[]
P. = QQ[]
A = 1
B = x^3 + x
tores = A - z*diff(B,x)
res = tores.resultant(B,x); factor(res)
res1 = res.univariate_polynomial()
sol1 = res1.roots(ring = QQbar)
with this code, I get the roots over QQbar, which is useful. Then I'd
like to move to the symbolic field and I do this:
var('x, zs', ns = 1)
from sage.symbolic.ring import NSR
As = NSR(A)
Bs = NSR(B)
Bs
x^3 + x
Bs.diff(x)
0
So, the derivative is not working. Which is the cause? It seems that
the "x" in Bs is not the "x" I declared, so the derivative gets 0 as a
result. Which is the reason?
Assuming to go on (manually for the moment), I do:
c1 = QQbar(sol1[0][0])
v1a = A - c1*(3*x^2 + 1)
Bs.gcd(v1a)
Traceback (click to the left for traceback)
...
RuntimeError: gcd: arguments must be polynomials over the rationals
Traceback (most recent call last):
File "", line 1, in
File "/home/notebook/sage_notebook/worksheets/admin/4/code/135.py",
line 9, in
Bs.gcd(v1a)
File "/usr/local/sage/local/lib/python2.5/site-packages/
zope.interface-3.3.0-py2.5-linux-i686.egg/", line 1, in
File "expression.pyx", line 1624, in
sage.symbolic.expression.Expression.gcd (sage/symbolic/expression.cpp:
8608)
RuntimeError: gcd: arguments must be polynomials over the rationals
My point is: even though I could get the roots in QQbar (which are
exact), it seems that Pynac is not happy to work with QQbar
quantities, the only supported seems to be QQ pure rationals.
Moreover, I don't see this being the right way to do this, because
(for this particular problem: integration) I don't like having the
numerical representation of things like sqrt(5), even if the result is
still correct, so that
temp = QQbar(sqrt(5)); temp
2.236067977499790?
temp^2
5.000?
So, please tell me. Which should be the right way to try to approach
this indefinite integration problem? You can see that I'm not that
good in deep mathematical theory, but approaching the simplest problem
(that could be different from this one I'm looking at right now) is
fun :)
Regards
Maurizio
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[sage-devel] Re: programming: define a new function
Thanks for the answer. As the time goes, I get more understanding of the complexity of the problem (much more than I expected at first). On 19 Apr, 02:27, Carl Witty wrote: > On Sat, Apr 18, 2009 at 2:46 PM, Maurizio wrote: > > Could you be clearer? As I told, I'm not familiar with rings. I don't > > even know the meaning of the argument of GF (I took the number 5 from > > an example I see in sage-support group, I think). Do you think that QQ > > [] could fit in this case? Moreover, what's the difference between QQ > > and QQbar? > > GF(5) means the Galois field of characteristic 5, a.k.a. the integers > modulo 5. (So in GF(5), you have 2*3 = 1, 3+4 = 2, etc.) It's > probably quite irrelevant for computing integrals. > Thank you, I should probably have looked for it on the internet rather than annoying you :) > QQ is the rational numbers (fractions). QQbar is the algebraic > closure of QQ; this means it includes every complex number which is > the root of a polynomial with rational coefficients. So it includes > things like sqrt(2) (which is a root of x^2-2), and sqrt(-1) (a root > of x^2+1), as well as more exotic numbers like the roots of x^5-x-1, > which can't be expressed using radicals (roots). (QQbar does not > include all complex numbers, though; for instance, it does not include > pi or e, which are transcendental rather than algebraic.) > I understand. This means (as I was kind of suspecting) that QQbar could have been a good candidate to try to work with (I am just trying to solve examples 1.4 and 1.5 of that web page). Unfortunately, QQbar doesn't provide resultant() yet, so it should jump in after the resultant has been calculated over QQ[]. I think that is not really an elegant solution (and probably very suboptimal...). > > Now let's go to Carl's help... > > >> Taking a quick look at that page, it looks like they want the exact > >> roots in CC of a polynomial with algebraic coefficients. In Sage, we > >> can get this with QQbar: > > >> sage: K. = QQbar[] > >> sage: (x^5-x-1).roots(ring=QQbar) > > > First problem with QQbar: it seems that resultant() doesn't like it, > > because it is not able to convert it to a Singular ring (this is the > > error, I'm not attaching all the output, tell me if you need it) > > > TypeError: no conversion of this ring to a Singular ring defined > > Looks like this hasn't been implemented yet. Unfortunately... > > > On the contrary, QQ[] seems to work fine with resultant (but it > > doesn't have roots() ) > > Univariate polynomials over QQ definitely have roots(); were you using > a multivariate polynomial ring? > Actually, I was using a multivariate polynomial ring to let SAGE understand the expression: tores = A - z*B.derivative(x) (by the way...wasn't there a trac opened to let derivative syntax unify to diff or something like that? it seems that singular doesn't like B.diff(x) yet... but that's very off-topic) if I don't define a ring containing x and z, how do I inject z into the workspace? certainly not as a symbolic variable, so what else? I know that at the very end this is a univariate polynomial ring root finding problem, I'm just wondering how to correctly manage it. > > Moreover, it seems that QQbar roots() is not working for multivariate > > polynomials ring... is it true or am I just missing something else? In > > that case, is possible to let it work in multivariate polynomials? As > > you can imagine, I would like to think about this as a method of > > solving integrals, so it is very likely to have a symbolic expression > > with more than just a single symbolic variable. > > > Apart from this, is there another way to solve an equation (with more > > than a single symbolic variable) obtaining exact roots? It seems that > > maxima would do the work (with algebraic numbers...), is it possible > > that it is the only symbolic equation solver within SAGE? What about > > SymPy or anything else? > > What does this even mean? .roots() gives a list of all the solutions > of a univariate polynomial equation. But a multivariate polynomial > equation will usually have an infinite number of solutions; for > instance, x^2+y^2-1=0 has an infinite number of solutions over the > rationals (or the reals, or the algebraic reals, etc.) > > If you have a system of multivariate polynomial equations, then the > system might have only finitely many solutions. > I understand, but let's consider the problem I'm coming from: indefinite integral. I'm not using polynomials because I'm well aware of the implications, rather because I found resultant() im
[sage-devel] Re: programming: define a new function
Carl, Burcin, thank you very much for your support. Burcin, I'm sorry for the trivial mistake. Thank you for pointing it out. Unfortunately, I don't understand this: " The theory only works over characteristic 0, i.e., your fields should contain QQ. Also note that, sage: P. = GF(5)[] sage: (x+x^5).derivative(x) 1 What is the integral of 1 w.r.t x in this case? " Could you be clearer? As I told, I'm not familiar with rings. I don't even know the meaning of the argument of GF (I took the number 5 from an example I see in sage-support group, I think). Do you think that QQ [] could fit in this case? Moreover, what's the difference between QQ and QQbar? About this: " You can get this information from the factorization you compute above. " It seems that factorization over GF(p) is broken (see http://groups.google.com/group/sage-devel/tree/browse_frm/thread/527e426dbfa04eda/2641f1509d1295db?rnum=1&_done=%2Fgroup%2Fsage-devel%2Fbrowse_frm%2Fthread%2F527e426dbfa04eda%3F#doc_2641f1509d1295db ), does it work for QQ? I don't seriously need factor, as long as I need the root finding next. Now let's go to Carl's help... > Taking a quick look at that page, it looks like they want the exact > roots in CC of a polynomial with algebraic coefficients. In Sage, we > can get this with QQbar: > > sage: K. = QQbar[] > sage: (x^5-x-1).roots(ring=QQbar) > First problem with QQbar: it seems that resultant() doesn't like it, because it is not able to convert it to a Singular ring (this is the error, I'm not attaching all the output, tell me if you need it) TypeError: no conversion of this ring to a Singular ring defined On the contrary, QQ[] seems to work fine with resultant (but it doesn't have roots() ) Moreover, it seems that QQbar roots() is not working for multivariate polynomials ring... is it true or am I just missing something else? In that case, is possible to let it work in multivariate polynomials? As you can imagine, I would like to think about this as a method of solving integrals, so it is very likely to have a symbolic expression with more than just a single symbolic variable. > [(1.167303978261419?, 1), > (-0.7648844336005847? - 0.3524715460317263?*I, 1), > (-0.7648844336005847? + 0.3524715460317263?*I, 1), > (0.181232698754? - 1.083954101317711?*I, 1), > (0.181232698754? + 1.083954101317711?*I, 1)] > > (AFAIK, maxima can't do this; I don't think maxima can handle general > algebraic numbers. Since Sage's solve() is implemented using maxima, > solve() won't work for this problem.) > > Carl Apart from this, is there another way to solve an equation (with more than a single symbolic variable) obtaining exact roots? It seems that maxima would do the work (with algebraic numbers...), is it possible that it is the only symbolic equation solver within SAGE? What about SymPy or anything else? Finally, I still would like to know which is the best way to translate the output of a calculation with polynomial rings into a symbolic expression, that can be carried on with maxima or pynac. Can you help me? Thank you very much Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: programming: define a new function
> For people interested in helping out, a few words about integration is > in order. As we discussed on this list before, many problems in > integration can be handled with heuristics before calling more advanced > algorithms. The heuristics also give more user friendly answers in most > cases. > > Integration code in Sage should run through some preprocessing before > calling anything else, be it maxima, or a native implementation of the > Risch algorithm. > > There are some links to descriptions of heuristics used by maxima and maple > at this page: > > http://wiki.sagemath.org/symbolics > > Pattern matching and rewriting capabilities of the new symbolics will > be very useful for this. Anybody interested in improving the > integration capabilities of Sage can help, no high level mathematical > knowledge is necessary. > This is very interesting, indeed I have no high level mathematical knowledge :) Just for fun, I was trying to implement the most basic examples (1.4 and 1.5) of this page, linked in the wiki: http://www.cs.uwaterloo.ca/~kogeddes/papers/Integration/IntSurvey.html Let me make this straight: I have not understood what is intended to be a resultant() and I have absolutely no experience with rings nor with multivariate polynomials. Nonetheless, I tried this code in SAGE: reset() P. = PolynomialRing(QQ) # P. = GF(5)[] A = -1 B = x^3 + x tores = A - z*B.derivative(x) res = tores.resultant(B,x); factor(res) I get: (-1) * (z + 1) * (2*z - 1)^2 That is somehow close to the result shown in the link, but why is it not identical? Moreover, why if I use the second statement (the one in the comment) to define the ring, do I get a completely different answer? E.g.: (z + 1) * (z + 2)^2 Which is the correct way to define the ring in this case? Finally, even assuming that I can get the right answer from this, which is the recommended way to get the roots of an equation given by a "univariate polynomials == 0"? This is supposed to be the next step of the algorithm. The worst way I can think of is to use repr(), so that I can use solve (), but hopefully there's a better way, at least to convert a polynomials to a symbolic expression... Is there? I know this is not leading anywhere... but thank you for your time! :) Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] programming: define a new function
Hi all. I'm willing to invest some of my time to understand if I can be able to do a step ahead with symbolic functions. How are special symbolic functions supposed to be defined? I am willing to experiment with delta of dirac function. This has some special properties (see http://en.wikipedia.org/wiki/Dirac_delta_function ), some of them are really useful but I don't know how to define them in a CAS like maxima or SAGE. I'm aware that it is already present in maxima, even though I don't think it is recognized by SAGE. I am wondering whether a viable approach could be to add to calculus.py a section similar to the one of Function_gamma, so that SAGE simply interfaces to maxima. I don't know if this is useful or not. Otherwise, I would be interested in knowing if this could be done with the new symbolic package. Burcin proved to be very helpful in showing me a simple way to define delta function by means of its values and he assigned it as being the derivative of heaviside function (defined in a sort of piecewise function): sage: heaviside(x).diff(x) dirac(x) is there a way to implement the other properties? I am willing to know if is there any documentation about that, because I am not able to find that! I am willing to learn something about pynac, but please feel free to discourage me if you think it is too far away from being ready. Is there any integration or derivation capability ready? Is it possible to start testing it using maxima's integration capabilities? (I don't think so...) I was browsing the todo page ( http://wiki.sagemath.org/symbolics/pynac_todo ) but it seems that many action items went away... are they already accomplished? (what about the TODO showed in http://wiki.sagemath.org/symbolics ?) I have to say I find the actual SAGE documentation seems pretty hard to browse, but could be my fault. Yesterday I lost half an hour looking for a "numerical solve" or something like that, before finding the "find_roots" function. Today, I spent half an hour looking for "differential equation solve" with no success. I am sure I could do some DE solution in the past (something with maxima, something with SymPy, I think, all through SAGE), but I think that I found the way to do it pretty easily browsing the old reference manual... Thanks a lot Maurizio PS: delta of dirac is already in SymPy ( http://code.google.com/p/sympy/issues/detail?id=672&can=1&q=dirac ), am I correct in thinking that the current function definition is different than SAGE? In this case, I assume this could be some good reading, but not necessarily a source of inspiration, right? --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: worksheet question: what does "Save & quit" do? What does "Discard & quit" do?
Hi everybody On Apr 13, 6:57 pm, John H Palmieri wrote: > So there are these buttons at the top of my worksheets saying "Save", > "Save & quit", "Discard & quit". What do they do? Do we need them? > Random comments: > > It seems to me that right now, "Save & quit" and "Discard & quit" do > the same thing: return to the list of active worksheets. For example, > I just opened a worksheet, made a tiny little change and hit "Discard > & quit". When I reopened the worksheet, the change was visible -- it > hadn't been discarded. So is there any actual difference between the > two? Should there be? If not, they should be consolidated into one > button: "Quit worksheet" or "Close worksheet". > I'd like to add my opinion. I think that the actual behavior is the most safe for my needs. It often happens to me that the notebook hangs on some complex calculation (sometimes it's just my fault!), and "interrupt" doesn't necessarily get me back the control of the notebook. Sometimes I can switch back to the home page and then get the notebook at the very same point where I was before the problem. So my point is that, in my opinion, getting the worksheet automatically saved each time a cell is modified or added, is a good thing (for me at least), and I'd like to keep this as an option, at least, if you decide to change the standard behavior. So, would be possible to keep a backup of the worksheet (when we open it), and then start working on the original worksheet, and then restore the original copy, if and only if the user decide to "discard" the changes? I know this is not really the standard way software are designed, but this seems to make sense to me. Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Taking DiracDelta from SymPy
Some time ago, I was annoying you guys for issues with transforms and stuff like that. On 20 Mar, 01:35, Maurizio wrote: > > So, up to now, my wishlist is: > - better Laplace, Fourier, Zeta, any othertransformmanagement > (especially in symbolic) > - unit of measurement integration > - extensible comparison between different implementations of all those > features in the different packages (better to do the limit/integral/ > anything else with maxima, or with sympy, or with sympycore, or with > pynac???) > - NEW: labels in the notebook :) colors would be VERY nice as well! > Just today, I went through this very interesting implementation of DiracDelta function in SymPy: http://code.google.com/p/sympy/issues/detail?id=672&can=1&q=diracdelta I know there is a lot of development undergoing pynac right now, so I would like Burcin et al. to deeply consider the implementation of this function (and Heaviside() and others needed) to speed up and make easier to deal with Fourier / Laplace (and any other) transform (series). Of course, I would really like to already have those functionalities already available in SymPy (I really go for Ondrej's really physics related approach to symbolics), but the basis are already there. I'm also hoping that SAGE's symbolics is considering this as a MUST :) This can be very useful now IMHO, even because integration is not yet assessed, so there is still room for design related thinking. Best regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: pynac switch todo list
On Mar 30, 5:36 pm, William Stein wrote:
> On Mon, Mar 30, 2009 at 8:08 AM, Maurizio wrote:
>
> > I would really like to not have to annoy you with this stuff, but I
> > really think I'm missing something important (and useful!!)
>
> > The first thing I have to say is: how do I check which is the type of
> > the coefficients (whether they are rationals or something else)? Even
> > when I do multivariate polynomials, I am comfortable with using
> > symbolic variables (probably I should switch, but I still have to
> > learn how to threat polynomials in SAGE).
>
> > One thing that really surprises me is: how comes in this simple
> > following example, expand() is so much slower than factor()? I often
> > do factor(expand(argument)) to be sure that factor is effective, and I
> > was supposing that expand() should have been so straightforward to not
> > require any particular computational effort! But look at this:
>
> > var('x1 x2')
> > var('u')
> > var('s')
> > var('a1 b1 c1 d1')
> > var('a2 b2 c2 d2')
> > var('e1 f1')
> > var('e2 f2')
>
> > A1 = matrix([[a1,b1],[c1,d1]])
> > A2 = matrix([[a2,b2],[c2,d2]])
> > B1 = matrix([[e1],[f1]])
> > B2 = matrix([[e2],[f2]])
>
> > var('D')
> > Am = D*A1 + (1-D)*A2
> > Bm = D*B1 + (1-D)*B2
> > Id=identity_matrix(parent(s),Am.nrows());
> > solm = (Am-Id*s)\(-Bm*u); solm
>
> > [u*(-e1*D - e2*(1 - D))/(a1*D + a2*(1 - D) - s) - (b1*D + b2*(1 -
> > D))*(u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
> > D))/(a1*D + a2*(1 - D) - s))/((a1*D + a2*(1 - D) - s)*((b1*D + b2*(1 -
> > D))*(-c1*D - c2*(1 - D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) -
> > s))]
> > [
> > (u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
> > D))/(a1*D + a2*(1 - D) - s))/((b1*D + b2*(1 - D))*(-c1*D - c2*(1 -
> > D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) - s)]
>
> > sol1 = solm[0];
> > time a = SR(repr(sol1)).factor()
>
> > Time: CPU 0.04 s, Wall: 0.17 s
>
> > time a = SR(repr(sol1)).expand()
>
> > Time: CPU 69.00 s, Wall: 116.28 s
>
> > Do you consider this acceptable?
>
> Of course not. Note that the above step that takes 116.28s on your
> computer takes 1.5 seconds on my laptop, so there is something weird
> about your computer. Using Pynac takes 0.01 seconds and Sympy takes
> 0.02 seconds.
>
> Using current Maxima-based symbolics:
>
> sage: reset()
> sage: var('x1 x2 u s a1 b1 c1 d1 a2 b2 c2 d2 e1 f1 e2 f2 D')
> (x1, x2, u, s, a1, b1, c1, d1, a2, b2, c2, d2, e1, f1, e2, f2, D)
> sage: sol1 = u*(-e1*D - e2*(1 - D))/(a1*D + a2*(1 - D) - s) - (b1*D + b2*(1 -
> D))*(u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
> D))/(a1*D + a2*(1 - D) - s))/((a1*D + a2*(1 - D) - s)*((b1*D + b2*(1 -
> D))*(-c1*D - c2*(1 - D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) -
> s));
> sage:
> sage: time g = sol1.expand()
> CPU times: user 0.40 s, sys: 0.03 s, total: 0.43 s
> Wall time: 1.59 s
>
I was fearing this happened because of the notebook. I can confirm
that even from the command line, the same commands you typed are
giving me the same results: MAXIMA based expand is taking forever...
Maybe by the time I finish writing this post, I'll tell you how much
time.
Here it is...
CPU times: user 57.80 s, sys: 1.67 s, total: 59.47 s
Wall time: 88.15 s
Please, consider that this is a workstation (not even a laptop) and
I'm running SAGE 3.3 (actually, upgraded from 3.2.3) in a virtual
machine with VMWare.
> Using Pynac:
>
> sage: var('x1 x2 u s a1 b1 c1 d1 a2 b2 c2 d2 e1 f1 e2 f2 D', ns=1)
> (x1, x2, u, s, a1, b1, c1, d1, a2, b2, c2, d2, e1, f1, e2, f2, D)
> sage: sol1 = u*(-e1*D - e2*(1 - D))/(a1*D + a2*(1 - D) - s) - (b1*D + b2*(1 -
> : D))*(u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
> : D))/(a1*D + a2*(1 - D) - s))/((a1*D + a2*(1 - D) - s)*((b1*D + b2*(1 -
> : D))*(-c1*D - c2*(1 - D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) -
> : s));
> sage:
> sage: time g = sol1.expand()
> CPU times: user 0.01 s, sys: 0.00 s, total: 0.01 s
> Wall time: 0.00 s
> sage: len(str(g))
> 9533
>
> Sympy is also fast for this sort of thing:
>
> sage: from sympy import var
> sage: var('x1 x2 u s a1 b1 c1 d1 a2 b2 c2 d2 e1 f1 e2 f2 D')
> (x1, x2, u, s, a1, b1, c1, d1, a2, b2, c2, d2, e1, f1, e2, f2, D)
> sage: x1,x2,u,s,a1,b1,c1,d1,a2,b2,c2,d2,e1,f1,e2,f2,D=var('x1 x2 u s
> a1 b1 c1 d1 a2 b2 c2 d2 e1 f1 e2 f2 D')
> sage: sol1 = u*(-e1*D - e2*(1 - D))/(a1*D + a2*(1 - D) - s) -
[sage-devel] Re: pynac switch todo list
I would really like to not have to annoy you with this stuff, but I
really think I'm missing something important (and useful!!)
The first thing I have to say is: how do I check which is the type of
the coefficients (whether they are rationals or something else)? Even
when I do multivariate polynomials, I am comfortable with using
symbolic variables (probably I should switch, but I still have to
learn how to threat polynomials in SAGE).
One thing that really surprises me is: how comes in this simple
following example, expand() is so much slower than factor()? I often
do factor(expand(argument)) to be sure that factor is effective, and I
was supposing that expand() should have been so straightforward to not
require any particular computational effort! But look at this:
var('x1 x2')
var('u')
var('s')
var('a1 b1 c1 d1')
var('a2 b2 c2 d2')
var('e1 f1')
var('e2 f2')
A1 = matrix([[a1,b1],[c1,d1]])
A2 = matrix([[a2,b2],[c2,d2]])
B1 = matrix([[e1],[f1]])
B2 = matrix([[e2],[f2]])
var('D')
Am = D*A1 + (1-D)*A2
Bm = D*B1 + (1-D)*B2
Id=identity_matrix(parent(s),Am.nrows());
solm = (Am-Id*s)\(-Bm*u); solm
[u*(-e1*D - e2*(1 - D))/(a1*D + a2*(1 - D) - s) - (b1*D + b2*(1 -
D))*(u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
D))/(a1*D + a2*(1 - D) - s))/((a1*D + a2*(1 - D) - s)*((b1*D + b2*(1 -
D))*(-c1*D - c2*(1 - D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) -
s))]
[
(u*(-f1*D - f2*(1 - D)) + u*(-c1*D - c2*(1 - D))*(-e1*D - e2*(1 -
D))/(a1*D + a2*(1 - D) - s))/((b1*D + b2*(1 - D))*(-c1*D - c2*(1 -
D))/(a1*D + a2*(1 - D) - s) + d1*D + d2*(1 - D) - s)]
sol1 = solm[0];
time a = SR(repr(sol1)).factor()
Time: CPU 0.04 s, Wall: 0.17 s
time a = SR(repr(sol1)).expand()
Time: CPU 69.00 s, Wall: 116.28 s
Do you consider this acceptable? I think there is some issue here!
Please, notice that this is SAGE 3.3... Is this a good reason to
upgrade? This is a multiuser environment, so it is slower to upgrade
than my laptop.
Another question: is possible that whenever I got Wall time much
higher than CPU time in factor, this should be recognized as a symptom
of having factor done via maxima? E.g.:
time igrFac = SR(repr(igrSol)).factor()
Time: CPU 0.51 s, Wall: 2.07 s
This is a completely different example. Also in this case, the expand
took forever to accomplish...
> Here's an example where the factorization could be done quickly via
> Singular, but isn't because we haven't bothered:
>
> sage: g = SR(f).subs(x=pi) # replace x by the transcendental pi
> sage: time g.factor()
> CPU times: user 0.02 s, sys: 0.01 s, total: 0.03 s
> Wall time: 1.55 s
About this point, does substitution by 0 matter as well to make
Singular unusable? This would be really bad, because I usually do
something like this:
simpleDict = {"rQ":0, "rCb":0, "rCf":0,"rLf":0}
[soluz[0][vCb].subs(simpleDict)
to simplify my expressions.
Last but not least. Do you think is this a reasonable way to work with
the solution of a linear system, represented by matrices? The matrices
are Aave, Bave, Cave, Dave (canonical dynamic system representation)
inVec = matrix([[gr],[ib]]); inVec
xVec = matrix([[vCb],[vCf],[iLf]]); xVec
sys = (Aave - I*w*Id)*xVec + Bave*inVec
xSys = [vCb,vCf,iLf]
soluz = solve(sys,xSys, solution_dict = True)
xSol = matrix([[soluz[0][vCb].subs(simpleDict)],[soluz[0][vCf].subs
(simpleDict)],[soluz[0][iLf].subs(simpleDict)]])
outVec = Cave*xSol + Dave*inVec
igrSol = SR(repr(outVec[0])).subs(simpleDict)
vbSol = SR(repr(outVec[1])).subs(simpleDict)
I fear that I'm confusing SAGE by going back and forth with different
packages, so this is taking me hours to do simple operations (am I
wrong) like expand(), factor(), collect() and others (especially
expand, as you could see!)
Many, many thanks
Maurizio
On Mar 30, 4:44 pm, William Stein wrote:
> On Mon, Mar 30, 2009 at 7:29 AM, Maurizio wrote:
>
> > I'm sorry... I wanted to say: is there any plan to make factor()
> > working with new symbolic as well? I could see one minute ago that
> > expand is already there (although I'm not aware whether is this
> > performed through maxima or not, but I don't think so, since it is a
> > built-in method for a pynac object).
>
> Yes, factor will work. I think it will work in cases involving only
> rational numbers, roots, and transcendentals by converting the
> expression to a multivariate polynomial and using sage's multivariate
> polynomial factorization (i.e., Singular).
>
> > Yes, the problem is that I found them quite slow, even though this
> > could arise from complex expressions. Unfortunately, I have not any
> > commercial software to compare with. Should I compare it with
> > evaluation time from working directly within maxima?
>
> For factoring ove
[sage-devel] Re: pynac switch todo list
I'm sorry... I wanted to say: is there any plan to make factor() working with new symbolic as well? I could see one minute ago that expand is already there (although I'm not aware whether is this performed through maxima or not, but I don't think so, since it is a built-in method for a pynac object). Yes, the problem is that I found them quite slow, even though this could arise from complex expressions. Unfortunately, I have not any commercial software to compare with. Should I compare it with evaluation time from working directly within maxima? Maurizio On Mar 30, 4:24 pm, William Stein wrote: > On Mon, Mar 30, 2009 at 7:19 AM, Maurizio wrote: > > > One question: is there any plan to replace expand(), factor() and > > other functions like these? > > Replace them with what? Do you mean, implement them? > > >I don't see them mentioned in the todo, > > and I always find their usage so much time consuming... > > Do you mean that they are too slow in the current symbolics? > > > > > > > Thanks > > > Maurizio > > > On Mar 29, 1:47 pm, Burcin Erocal wrote: > >> Hi, > > >> I put up a preliminary todo list for the switch to pynac here: > > >>http://wiki.sagemath.org/symbolics/switch_todo > > >> I made the list by changing the default of the "var" command to create > >> pynac variables, and running the doctests. Looking at the results I > >> realised that I should have made other changes, such as export the new > >> symbolic ring (NSR) to the command line as SR. These are listed in the > >> first section of that page. > > >> Next section gives a list of methods which the pynac symbolic > >> expressions (sage.symbolic.expression.Expression) need to implement. > >> The last section is miscellaneous stuff I didn't want to classify > >> further. > > >> Some time next week, I will put a clean version of the switchover > >> patch, along with a new pynac package and some fixes to the sage > >> library so others can reproduce the results above. > > >> After looking through the errors caused by the switch, I have a few > >> questions: > > >> - Syntax for derivative and integrate functions: > > >> Current symbolics allows this: > > >> sage: (x^2).integrate() > >> x^3/3 > > >> I propose to make the integration variable explicit, by deprecating > >> this use, and encouraging the use of this: > > >> sage: (x^2).integrate(x) > >> x^3/3 > > >> Note that the MMA syntax for Integrate also asks for the variable > >> explicitly. > > >> Same goes for .derivative(), current symbolics works without specifying > >> a variable. While this usage might be ok in a univariate polynomial > >> ring, where the variable is known already, I think it's better to ask > >> the user to explicitly state the variable. > > >> - What do we do with the old tests? > > >> In the sage/calculus/ directory there are files which contain only > >> tests. What shall I do with these? Copy them to sage/symbolics/test, > >> change the old ones to use old symbolics variables to test the old > >> code, and make the new copies test the new code? > > >> Or, what do you think should happen to the old code? How long are we > >> going to keep it around? > > >> Comments? > > >> Cheers, > >> Burcin > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: pynac switch todo list
One question: is there any plan to replace expand(), factor() and other functions like these? I don't see them mentioned in the todo, and I always find their usage so much time consuming... Thanks Maurizio On Mar 29, 1:47 pm, Burcin Erocal wrote: > Hi, > > I put up a preliminary todo list for the switch to pynac here: > > http://wiki.sagemath.org/symbolics/switch_todo > > I made the list by changing the default of the "var" command to create > pynac variables, and running the doctests. Looking at the results I > realised that I should have made other changes, such as export the new > symbolic ring (NSR) to the command line as SR. These are listed in the > first section of that page. > > Next section gives a list of methods which the pynac symbolic > expressions (sage.symbolic.expression.Expression) need to implement. > The last section is miscellaneous stuff I didn't want to classify > further. > > Some time next week, I will put a clean version of the switchover > patch, along with a new pynac package and some fixes to the sage > library so others can reproduce the results above. > > After looking through the errors caused by the switch, I have a few > questions: > > - Syntax for derivative and integrate functions: > > Current symbolics allows this: > > sage: (x^2).integrate() > x^3/3 > > I propose to make the integration variable explicit, by deprecating > this use, and encouraging the use of this: > > sage: (x^2).integrate(x) > x^3/3 > > Note that the MMA syntax for Integrate also asks for the variable > explicitly. > > Same goes for .derivative(), current symbolics works without specifying > a variable. While this usage might be ok in a univariate polynomial > ring, where the variable is known already, I think it's better to ask > the user to explicitly state the variable. > > - What do we do with the old tests? > > In the sage/calculus/ directory there are files which contain only > tests. What shall I do with these? Copy them to sage/symbolics/test, > change the old ones to use old symbolics variables to test the old > code, and make the new copies test the new code? > > Or, what do you think should happen to the old code? How long are we > going to keep it around? > > Comments? > > Cheers, > Burcin --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
Hi everybody. I see this discussion is getting less focus in this moment. I am fine with this, I see people has a lot of stuff to do. At the same time, would you please consider updating the open ticket on SAGE: http://trac.sagemath.org/sage_trac/ticket/3852 I think this would make at least this discussion useful for the future. Best regards Maurizio On 23 Mar, 22:37, Maurizio wrote: > People, > I'm really glad about having brought this discussion to a reasonably > interesting level. > > From now on, I can't give any other comment (I can't deal with code so > specific issues), but I'd like to hear those coming from the > mantainers ofSAGE. > As far as I'm concerned, I was trying to get the attention of > Quantities' developers, and I think I accomplished this in a fairly > satisfying way. I can try to give my comments now, but the situation > now seems to be tightly related on whether there is any chance that > anybody works on anything. > So, words are becoming less important than actions in this phase, in > my opinion. > By the way, to me, it doesn't seem that dealing with numpy quantities > should be a big deal (at least for the time being), otherwise how > comes are we using already numpy for numerical stuff at the moment? I > know this could be bad for my final aim (that is, bringing physical > units to a higher degree of functionalities, related to polynomials > and symbolic, and I've seen that other people have interest in this), > because maybe getting this simple feature could calm down this > discussion and let people forget this issue. > > To connect to the other discussion we are having in this days, I think > this engineering related features should be enhanced and stressed (and > possibly clearly documented), and I don't think this needs to create > another distribution ofSAGE, the current one is very good and I'd > like to have a single version. > > I still encourage you guys to at least give your comments > > Regards and thanks everybody > > Maurizio > > On 23 Mar, 21:03, Robert Bradshaw > wrote: > > > On Mar 22, 2009, at 6:49 AM, Darren Dale wrote: > > > > On Mar 20, 10:31 pm, Jason Grout wrote: > > >> Maurizio wrote: > > >>> Not yet... I think I was previously asking whether some of you guys > > >>> are interested in trying to contact them, if you do think it does > > >>> makes sense. > > > >>> I mean, if this community is interested in having this feature, the > > >>> Quantities developers are going to find some good feedback, > > >>> otherwise, > > >>> we could just probably end up losing a good occasion, because things > > >>> are not ready yet (although I hope that's not the case)! > > > >> I think there are a good number of people now that would like to have > > >> the feature, and as you well know, there are lots and *lots* of > > >> future > > >> users that would like to have the functionality. > > > >> I'd say it's time to contact them and see if they can help. If there > > >> needs to be changes made to Quantities, then making them now, > > >> while it > > >> is still solidifying, would be advantageous. > > > > Hello, I am Darren Dale, the developer of Quantities. Thank you > > > Maurizio for contacting me. > > > Glad to hear from you. > > > [...] > > > > I guess the question I have for this list is, what would be required > > > for quantities to work insage? I would prefer to try to work out the > > > numpy issues I alluded to before quantities gets too much exposure, in > > > case changes in API are required (unlikely). > > > Am I correct in understanding that the values in Quantities all need > > to be NumPy values? If this is the case, it probably boils down to > > NumPy's not handling of non-Python types. This really needs to get > > resolved. > > > - Robert > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: notebook share button
Thank you for pointing this out. Honestly, that wasn't really my main point. I just wanted to point out that SAGE has the capabilities to become a powerful tool to be actually used by engineers during their job, rather than being a very beautiful toy. So, in my opinion I would prefer to get those improvements I was talking about in the previous posts Regards Maurizio On 29 Mar, 15:38, Jaap Spies wrote: > Jason Grout wrote: > > Maurizio wrote: > >> Let me throw this stone, it's just something that pops into my mind > >> now: do you know what simulink is? That is a unique feature of MatLab > >> (actually it's a toolbox), which has been pathetically replicated by > >> somebody, but with no results in my opinion. To the best of my > >> knowledge, I actually see SAGE as a viable platform to possibly work > >> on something like that, even though we are MILES away to have the > >> chance to do that. Before, we should use this brick to build all the > >> necessary engineering walls, because we really need a comfortable > >> building first, to think about such an additional package... > >> My point is that we have a chance here, for something useful not only > >> to mathematician, but also to a whole world of people, long awaiting > >> for something to free them from the boring and expensive chain of > >> Matlab and Mathcad and Mathematica... > > >> My 2 cents > > > We've had some threads on Simulink (and the scilab version of simulink) > > before. You're right; we don't have sufficient framework for it right > > now. It's certainly come up before, and I'm sure it will again. I'm > > not sure anyone has very much experience with it, though. > > > There have been some attempts at some similar functionality in python. > > It would be interesting for someone that is familiar with simulink (and > > the audience simulink addresses) to comment on what is available in > > python or what is available, maybe in C, that could be wrapped by Sage. > > How about: > PyLab_Works is a free and open source replacement for LabView + MatLab, > written in pure Python. PyLab_Works is a visual design package, much easier > to learn and > to extend than LabView. PyLab_Works also supports a MatLab-like environment > for doing scientific and engineering calculations but with a much better > general > programming environment (thanks to Python + Scipy) than MatLab. Even kids can > use it! > > See:http://code.google.com/p/pylab-works/ > > Jaap > > > You also might find it interesting to search the archives for Simulink. > > > Jason > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Custom folders in notebook (Was Re: sage-moodle integration )
There has been some discussions about it at: http://groups.google.com/group/sage-devel/tree/browse_frm/thread/304a39b13cf27990/e7437b268ad918c9?rnum=1&q=notebook+folders&_done=%2Fgroup%2Fsage-devel%2Fbrowse_frm%2Fthread%2F304a39b13cf27990%2Fe22461daf01e3a1c%3Flnk%3Dgst%26q%3Dnotebook%2Bfolders%26#doc_af0fd228b7ec06d8 It seems that developers are more oriented towards labels (like gmail) than folders, and I personally agree with this choice. Another thing discussed in the same thread is coloring... I'm wondering if the code dependent coloring in the notebook has been considered as a possible enhancement. This would be really useful to improve notebook usability. At the very end, I'm afraid we would be implementing something like Notepad++ (just an example) within the browser... Isn't there any firefox plugin or stuff like that to directly provide this? Thanks Maurizio On 28 Mar, 12:49, Golam Mortuza Hossain wrote: > On Sat, Mar 28, 2009 at 7:20 AM, pang wrote: > > > 2) Organization and sharing: sage notebooks aren't organized in > >foldersand they aren't attached to a calendar. They all appear in a > > single long list. > > +1. It would be really good to have a feature for creating > customfoldersinnotebookinterface. While working with more than one > project using Sage, I often see myself opening the wrongnotebook. > It will be really helpful, if I could create a folder say "Project_foo" > and then keep all related notebooks under this folder. > > Thanks, > Golam --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: REDUCE now available under BSD-like license
I don't get it... how should this make SAGE easier? From my point of view, I don't even remember anymore (my bad I know) what a ring represent, but this is not slowing down my SAGE learning, I think. But what if tomorrow or the day after, I do need those? I'm sorry, I just don't get the point of removing stuff for engineers, how could this help them (I should say, us)? I think good examples and documentation would be SO MUCH better to have! My 2 cents Maurizio On 25 Mar, 16:09, rjf wrote: > I think that you probably miss the point. Most engineers are not > trained in number theory, group theory, advanced algebra, etc. Leaving > these parts out of Sage would potentially make it easier to use. But > then maybe the engineer should use Maxima, or one of those other > systems that either ignores the central "pure math only" computational > parts of Sage, or relegates them to some less-prominent position. > RJF > > On Mar 25, 6:32 am, Stan Schymanski wrote: > > > I am an example for someone that does use both modes. I do symbolic > > derivations and transformations and then apply them to data, so I fancy > > a system where both symbolic evaluations and numerical approximations > > can be done transparently. If one is only interested in numerical > > evaluations, why not use e.g. Octave? In my opinion, installing only a > > set of numerical tools or only a set of symbolic tools in Sage would > > amount to crippling a great piece of software, so if such an option was > > made possible we should make sure that a message is plastered all over > > the interface to make sure people don't confuse this with the real Sage. > > > I apologise in advance if I misunderstood the context of this thread. > > > Cheers > > Stan > > > Pablo Angulo wrote: > > >> It's all about acquiring a bigger audience in the applied fields. > > >> There is certainly the impression out there that Sage is MAINLY a CAS > > >> system (as opposed to a numerical system), and more geared towards > > >> pure mathematicians than engineers, physicists, and applied > > >> scientists. A separate and clear way to configure or to download an > > >> engineering version (say through a separate webpage), that is well > > >> advertised, would go a long way in helping Sage as a whole. Just my > > >> humble opinion. > > > > I found some of sage features a bit of a mess the first times I did > > > numerical computation in sage, like using Reals and Integers instead of > > > float or ints, or using rationals and symbolic expressions for radicals. > > > > But I think a numerical mode would be a better choice. Selecting python > > > in the drop list gets you closer to that, but it still yields the > > > symbolic sqrt(2) instead of the numerical approximation, for example. > > > > Just loading math.sqrt instead of sqrt and taking similar choices of > > > loaded packages would be enough for me, with same interface and package > > > base. Like me, I think many people would use one mode or the other, > > > depending on the task, so installing both the standard and the applied > > > versions would not be saving any space. > > > > Regards > > > Pablo > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: z-transform, was: REDUCE now available under BSD-like license
Robert, thank you very much for clarifying this. Could you please point us to some examples (if documentation is not that good) for the improved laplace transform? I strongly stress that having good examples about code use for engineers would be SO MUCH appreciated. Do you think that wiki pages are too slow to produce? Do you think that maybe publishing example notebooks would be easier? For people not aware of this (as I was some minutes ago) I'd like to point out that maxima code contributed by others can be downloaded at: http://maxima.cvs.sourceforge.net/viewvc/maxima/maxima/share/contrib/ Thank you very much Maurizio On 23 Mar, 16:16, Robert Dodier wrote: > Minh Nguyen wrote: > > As regards a Maxima package for z transform, I think Alasdair McAndrew > > has written such a package about 2 years ago. > > More recently I've written some z-transform code which I think is > more extensive than the stuff that was written before. > It is maxima/share/contrib/z_transform.mac and rtest_z_transform.mac > in Maxima CVS. It will be included in the next (5.18) release. > There isn't any documentation yet although the test script has some > examples. > > On a related note, lately there have been improvements in the > Laplace transform courtesy of Dieter Kaiser. > > FWIW > > Robert Dodier --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
People, I'm really glad about having brought this discussion to a reasonably interesting level. >From now on, I can't give any other comment (I can't deal with code so specific issues), but I'd like to hear those coming from the mantainers of SAGE. As far as I'm concerned, I was trying to get the attention of Quantities' developers, and I think I accomplished this in a fairly satisfying way. I can try to give my comments now, but the situation now seems to be tightly related on whether there is any chance that anybody works on anything. So, words are becoming less important than actions in this phase, in my opinion. By the way, to me, it doesn't seem that dealing with numpy quantities should be a big deal (at least for the time being), otherwise how comes are we using already numpy for numerical stuff at the moment? I know this could be bad for my final aim (that is, bringing physical units to a higher degree of functionalities, related to polynomials and symbolic, and I've seen that other people have interest in this), because maybe getting this simple feature could calm down this discussion and let people forget this issue. To connect to the other discussion we are having in this days, I think this engineering related features should be enhanced and stressed (and possibly clearly documented), and I don't think this needs to create another distribution of SAGE, the current one is very good and I'd like to have a single version. I still encourage you guys to at least give your comments Regards and thanks everybody Maurizio On 23 Mar, 21:03, Robert Bradshaw wrote: > On Mar 22, 2009, at 6:49 AM, Darren Dale wrote: > > > > > On Mar 20, 10:31 pm, Jason Grout wrote: > >> Maurizio wrote: > >>> Not yet... I think I was previously asking whether some of you guys > >>> are interested in trying to contact them, if you do think it does > >>> makes sense. > > >>> I mean, if this community is interested in having this feature, the > >>> Quantities developers are going to find some good feedback, > >>> otherwise, > >>> we could just probably end up losing a good occasion, because things > >>> are not ready yet (although I hope that's not the case)! > > >> I think there are a good number of people now that would like to have > >> the feature, and as you well know, there are lots and *lots* of > >> future > >> users that would like to have the functionality. > > >> I'd say it's time to contact them and see if they can help. If there > >> needs to be changes made to Quantities, then making them now, > >> while it > >> is still solidifying, would be advantageous. > > > Hello, I am Darren Dale, the developer of Quantities. Thank you > > Maurizio for contacting me. > > Glad to hear from you. > > [...] > > > I guess the question I have for this list is, what would be required > > for quantities to work in sage? I would prefer to try to work out the > > numpy issues I alluded to before quantities gets too much exposure, in > > case changes in API are required (unlikely). > > Am I correct in understanding that the values in Quantities all need > to be NumPy values? If this is the case, it probably boils down to > NumPy's not handling of non-Python types. This really needs to get > resolved. > > - Robert --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: REDUCE now available under BSD-like license
> > I'm not really familiar with Reduce, and am not a CAS developer. I am > a kind of "interested observer" and I try to be helpful by collecting > info about existing CAS systems and ideas and submitting links to the > experts - you guys. > > Since I am alot more familiar with physics/engineering/numerical > applications, I wonder if you think it would be a good idea to > maintain a version of Sage geared towards these types of applications, > especially now that Scilab and Reduce have been released as GPL- > compatible. > > Cheers, > > Hazem > Thank you very much Hazem Honestly, I'm not aware of REDUCE capabilities, but I totally share Hazem's point of view. Just having a look at that article, I can see some interest for us to share (for example) the Z-transform features of REDUCE with any scientist/engineer out there. I'm not saying we should include REDUCE, also because I don't know whether maxima guys at least made z transform available, but I think we should at least consider taking some advantage from their open source code, especially if we are now working so hard in our own symbolic package. Could pynac take advantage of this? Regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: complex plot
I agree... but what about magnitude and argument of the complex number? I find this representation often more useful than real and imaginary, so I think it's just a matter of the application. +1 from me Maurizio On 21 Mar, 22:28, Henryk Trappmann wrote: > As I see there are no specific plot commands for complex functions. > There are 3 types that would be preferable: > 1. parametric plot > 2. contour plot > 3. conformal plot > > The parametric plot can be simulated with parametric_plot and the > contour plot with contour_plot. > However for these functions one have to specify the input as a pair of > functions. > When you have a complex function f, the input would be: > (lambda z: real(f(z)), lambda z: imag(f(z))) > > The problem with this simulation is that f has to be computed twice to > obtain the real and the imaginary part. > If you have a very computation intensive function f this is deadly. > So it would be great if the parametric_plot and contour_plot had an > option for complex functions that would avoid these double > computations. > More generally parametric_plot and countour_plot could take a > functions that returns a pair of values in addition to taking a pair > of functions. > > Is this problem already recognized? I also would be willing to > implement such a functionality if not. Any comments? --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Fwd: Quantities chance to spread
I've opened a question on their launchpad project: https://answers.edge.launchpad.net/python-quantities/+question/64894 I hope you guys share my feelings, so that I've been a good ambassador Regards Maurizio On 21 Mar, 19:28, Jason Grout wrote: > Maurizio wrote: > > Is any of you guys a launchpad member? > > I'm not able to contact the Quantities developers, this is the email I > > sent to their mailing list, but it has probably been filtered because of > > not being a developer. Jason can you forward this to the Quantities > > developers? > >https://edge.launchpad.net/~python-quantities-developers > > Yes, it looks like you have to join launchpad to see the emails, mail > the mailing list, etc. Could you join and be the point person between > Sage and Quantities? > > Thanks, > > Jason > > > > > Thanks > > Maurizio > > > -- Forwarded message -- > > From: *Maurizio Granato* > <mailto:maurizio.gran...@gmail.com>> > > Date: Sat, Mar 21, 2009 at 2:39 PM > > Subject: Quantities chance to spread > > To: python-quantities-develop...@lists.launchpad.net > > <mailto:python-quantities-develop...@lists.launchpad.net> > > > Hello guys, > > > I'm Maurizio, an electronic engineer who greatly appreciate the chance > > to work with all the python-powered tools nowadays freely available on > > the internet. > > > I discovered Quantities just a couple of days ago, and I'm very > > interested in taking advantage out of it. > > > Since I'm currently using SAGE (http://www.sagemath.org/), I was eager > > to install Quantities in SAGE. I don't know whether you are aware of it, > > SAGE is a free open-source <http://hg.sagemath.org/> mathematics > > software system, that combines the power > > <http://www.sagemath.org/tour.html> of many existing open-source > > packages <http://www.sagemath.org/links-components.html> into a common > > Python-based interface. From this point of view, Quantities addition > > makes perfect sense to me, to enhance engineering capabilities of SAGE: > > it is already very powerful, both in terms of numeric computation, since > > it includes *numpy and scipy*, and in terms of symbolic calculus, since > > it includes *sympy *and it greatly interfaces with *maxima*. > > > SAGE developers' aim is to provide an open source alternative to MatLab, > > Mathematica (and I would add Mathcad as well, because of the very nice > > html powered available interface), so having a physical quantities > > management should be a "must" feature. > > > As you can see here: > >http://groups.google.com/group/sage-devel/browse_frm/thread/ae18ce618... > > I've proposed to include Quantities in SAGE, but unfortunately this is > > not directly possible, since SAGE deals with numbers not in the straight > > Python way. I've seen a lot of interest from the SAGE community in it, > > and it seems that they would greatly appreciate if you would consider to > > work a little bit (it seems that just some minor modifications would be > > necessary) to let quantities work in SAGE. A long term idea could be > > also to make quantities deal with the already present symbolic > > capabilities, that would allow for such an interesting scenario!! > > I consider this a win-win strategy, because this would add a very useful > > feature to SAGE, and would give you guys a great exposure, and a lot of > > bug reporting, I think. > > > Please, I also would like you to consider what I proposed in that > > mailing list for physical quantities management: please have a look at > > MESSAGE #16 of the thread I previously mentioned. My idea is to let the > > user add physically homogeneous quantities (like centimeters and > > millimeters, or milliVolts and Volts) and then produce the result in the > > more convenient way. I've derived this good habit from my CASIO > > calculator, that has been so useful and comfortable to use during all > > the years of my study and my work. I have already been able to do this > > with a one line modification in quantities source to do this. > > > Thank you very much for considering this, even just your comments on the > > SAGE group would be greatly appreciated. > > > Keep up the good work! > > > Best regards > > > Maurizio > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Fwd: Quantities chance to spread
Is any of you guys a launchpad member? I'm not able to contact the Quantities developers, this is the email I sent to their mailing list, but it has probably been filtered because of not being a developer. Jason can you forward this to the Quantities developers? https://edge.launchpad.net/~python-quantities-developers Thanks Maurizio -- Forwarded message -- From: Maurizio Granato Date: Sat, Mar 21, 2009 at 2:39 PM Subject: Quantities chance to spread To: python-quantities-develop...@lists.launchpad.net Hello guys, I'm Maurizio, an electronic engineer who greatly appreciate the chance to work with all the python-powered tools nowadays freely available on the internet. I discovered Quantities just a couple of days ago, and I'm very interested in taking advantage out of it. Since I'm currently using SAGE ( http://www.sagemath.org/ ), I was eager to install Quantities in SAGE. I don't know whether you are aware of it, SAGE is a free open-source <http://hg.sagemath.org/> mathematics software system, that combines the power <http://www.sagemath.org/tour.html> of many existing open-source packages <http://www.sagemath.org/links-components.html> into a common Python-based interface. From this point of view, Quantities addition makes perfect sense to me, to enhance engineering capabilities of SAGE: it is already very powerful, both in terms of numeric computation, since it includes *numpy and scipy*, and in terms of symbolic calculus, since it includes *sympy *and it greatly interfaces with *maxima*. SAGE developers' aim is to provide an open source alternative to MatLab, Mathematica (and I would add Mathcad as well, because of the very nice html powered available interface), so having a physical quantities management should be a "must" feature. As you can see here: http://groups.google.com/group/sage-devel/browse_frm/thread/ae18ce618abd66d2I've proposed to include Quantities in SAGE, but unfortunately this is not directly possible, since SAGE deals with numbers not in the straight Python way. I've seen a lot of interest from the SAGE community in it, and it seems that they would greatly appreciate if you would consider to work a little bit (it seems that just some minor modifications would be necessary) to let quantities work in SAGE. A long term idea could be also to make quantities deal with the already present symbolic capabilities, that would allow for such an interesting scenario!! I consider this a win-win strategy, because this would add a very useful feature to SAGE, and would give you guys a great exposure, and a lot of bug reporting, I think. Please, I also would like you to consider what I proposed in that mailing list for physical quantities management: please have a look at MESSAGE #16 of the thread I previously mentioned. My idea is to let the user add physically homogeneous quantities (like centimeters and millimeters, or milliVolts and Volts) and then produce the result in the more convenient way. I've derived this good habit from my CASIO calculator, that has been so useful and comfortable to use during all the years of my study and my work. I have already been able to do this with a one line modification in quantities source to do this. Thank you very much for considering this, even just your comments on the SAGE group would be greatly appreciated. Keep up the good work! Best regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: notebook share button
thank you for adding fuel! :) I honestly think that SAGE's user target should be slightly different from that one. I mean, picking data from hardware drivers is just a matter of companies agreement and capability to crunches large quantities of data. In this software, on the contrary, I see a powerful symbolic calculus capability, which is not that easy to find! I see a big number of design engineers out there, whose interest is system modeling, system design, system analysis, and I don't see any capability to accomplish this without any powerful symbolic or analytical system (unless you just prefer to do thousands of simulations...). Moreover, it's very important to deal with interfacing the analysis results to data arrays of reasonable size. In this way, the engineer is enabled to verify and match the analysis versus some simulation or experimental results, without necessarily needing to physically connect the measurement hardware to the pc. Most of the time, a couple of waveforms is more than enough! I have been able to take some advantage of MAXIMA in the past, but the reality is that SAGE has some added value in this field: 1) nice and powerful data and analysis representation (I LOVE the notebook) 2) easy sharing within a network (I LOVE the notebook) 3) easy interfacing with additional external packages 4) easy interfacing to numerical packages (like numpy) Do you see why I do like SAGE? And I do see a LOT of potential for the engineering world!! But I think we need some effort to further develop that... hopefully I'll push for that :) Regards Maurizio Let me throw this stone, it's just something that pops into my mind now: do you know what simulink is? That is a unique feature of MatLab (actually it's a toolbox), which has been pathetically replicated by somebody, but with no results in my opinion. To the best of my knowledge, I actually see SAGE as a viable platform to possibly work on something like that, even though we are MILES away to have the chance to do that. Before, we should use this brick to build all the necessary engineering walls, because we really need a comfortable building first, to think about such an additional package... My point is that we have a chance here, for something useful not only to mathematician, but also to a whole world of people, long awaiting for something to free them from the boring and expensive chain of Matlab and Mathcad and Mathematica... My 2 cents On 20 Mar, 02:02, kcrisman wrote: > > So, up to now, my wishlist is: > > - better Laplace, Fourier, Zeta, any other transform management > > (especially in symbolic) > > - unit of measurement integration > > - extensible comparison between different implementations of all those > > features in the different packages (better to do the limit/integral/ > > anything else with maxima, or with sympy, or with sympycore, or with > > pynac???) > > - NEW: labels in the notebook :) colors would be VERY nice as well! > > Just to add fuel to the fire, I was told point-blank by one of my > colleagues that unless Sage (or Octave or any other OSS) haddrivers > to connect to measurementhardwarein his labs, he didn't see the > point of trying to use Sage, because vendors supply/selldrivers > hooking Matlab to the type of equipment he uses, and he wasn't about > to write a driver. > > I don't really know whether this is true or not (that is, that it's > too annoying to get data into Sage directly from things) and I don't > even know exactly what sort of measurement device he was talking > about, but this seems very plausible, as well as something the current > developer network is not going to be able to solve any time soon. > Food for thought, at least, esp. since a large piece of the current > college calculus market is pre-engineers (see David Bressoud's recent > articles in the Notices and FOCUS, e.g.) and those are the future > users of Sage or any other similar program. > > - kcrisman --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
Not yet... I think I was previously asking whether some of you guys are interested in trying to contact them, if you do think it does makes sense. I mean, if this community is interested in having this feature, the Quantities developers are going to find some good feedback, otherwise, we could just probably end up losing a good occasion, because things are not ready yet (although I hope that's not the case)! Regards Maurizio On 20 Mar, 01:01, Jason Grout wrote: > Maurizio wrote: > > Hi > > > can anyone give an advice on how to adapt Quantities to let it be > > compatible with SAGE? I don't know how SAGE modifies the way to > > represent numbers, and why it does not comply with Quantities. > > Have you asked the Quantities developers to look at this thread? My > guess is that they would be very interested in having Quantities > integrated in with Sage, as it immediately gives them a far greater user > base and exposure (and bug reports!) than otherwise. Besides, they > would probably be better able to work on this than most other people. > > Thanks, > > Jason --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: notebook share button
Hi Minh, you got the Bode plot I was talking about. Please, try to compare it to our demo (we talked about that in this thread: http://groups.google.com/group/sage-devel/browse_frm/thread/221ebcb20940d8dc/94e1551399325c5c?lnk=gst&q=bode+plot#94e1551399325c5c): The demo is at this notebook: http://www.sagenb.org/pub/285/ Even though this has just a minor percentage of the whole lot of possibility there, I'm still quite happy about that, I really hope you guys have a look at that. I hope your patience stays always this high, as you can see, I'm not giving up so easily ;) Maurizio On 20 Mar, 00:48, Minh Nguyen wrote: > Hi Maurizio, > > On Thu, Mar 19, 2009 at 11:35 PM, Maurizio wrote: > > > I hope I didn't get misunderstood :) > > > From my point of view, I was talking about enhancing the engineer > > oriented SAGE functions. > > OK, I thought you meant the *software* engineering part of Sage > itself, as opposed to say the features that are useful for an > engineer. Thank you very much for clarifying this issue, and your > growing wish list is certainly very welcome. Keep them coming! > > > My personal list is continuously growing as long as I use SAGE (it's > > just 4 months now...not that much). > > > For example, my first concern was how to produce nice and useful Bode > > plots. I could figure out how to do that with matplotlib (even though > > I would have appreciated something like a semilogx or loglog plot > > function, please forgive me but I have used Matlab for so long!). > > Then I didn't like the inability to zoom and pan within those plots. > > And so, mostly thanks to Kenny's help, I was able to have Bode plots > > in FLOT, which allows me some beautiful online interaction (I mostly > > use the notebook). > > With regards to Bode plot, do you mean something like the following? > > http://en.wikipedia.org/wiki/Bode_plot > > > > > Then, I went through the integration issues, and Laplace and Fourier > > transform. In SAGE there is no support for delta functions, step > > functions, and all those important features for powerful symbolic > > representation in these transform domains. > > > Then, I recalled how useful was unit of measurements management with > > Mathcad, and now I'm trying to deal with it. > > > So, up to now, my wishlist is: > > - better Laplace, Fourier, Zeta, any other transform management > > (especially in symbolic) > > - unit of measurement integration > > - extensible comparison between different implementations of all those > > features in the different packages (better to do the limit/integral/ > > anything else with maxima, or with sympy, or with sympycore, or with > > pynac???) > > - NEW: labels in the notebook :) colors would be VERY nice as well! > > > I hope you don't ban me, > > No offense taken. > > Keep the feature requests coming. It's one way of knowing what's > missing in Sage. I personally think that developers of maths software > should be attuned to their users. > > > but I can tell you I will come with many more > > requests soon... I'm afraid to be to annoying, but I really enjoy this > > stuff! Many thanks! > > -- > Regards > Minh Van Nguyen --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: notebook share button
I hope I didn't get misunderstood :) >From my point of view, I was talking about enhancing the engineer oriented SAGE functions. My personal list is continuously growing as long as I use SAGE (it's just 4 months now...not that much). For example, my first concern was how to produce nice and useful Bode plots. I could figure out how to do that with matplotlib (even though I would have appreciated something like a semilogx or loglog plot function, please forgive me but I have used Matlab for so long!). Then I didn't like the inability to zoom and pan within those plots. And so, mostly thanks to Kenny's help, I was able to have Bode plots in FLOT, which allows me some beautiful online interaction (I mostly use the notebook). Then, I went through the integration issues, and Laplace and Fourier transform. In SAGE there is no support for delta functions, step functions, and all those important features for powerful symbolic representation in these transform domains. Then, I recalled how useful was unit of measurements management with Mathcad, and now I'm trying to deal with it. So, up to now, my wishlist is: - better Laplace, Fourier, Zeta, any other transform management (especially in symbolic) - unit of measurement integration - extensible comparison between different implementations of all those features in the different packages (better to do the limit/integral/ anything else with maxima, or with sympy, or with sympycore, or with pynac???) - NEW: labels in the notebook :) colors would be VERY nice as well! I hope you don't ban me, but I can tell you I will come with many more requests soon... I'm afraid to be to annoying, but I really enjoy this stuff! Many thanks! Regards Maurizio On 20 Mar, 00:20, Minh Nguyen wrote: > Hi Maurizio, > > On Thu, Mar 19, 2009 at 9:26 PM, Maurizio wrote: > > > > > PS: I still encourage you to improve engineering features ;) > > Just to prevent misunderstanding on my part, is it possible for you to > give an (incomplete) list of engineering features you have in mind, or > engineering features you think should be improved? > > For example, with a Sage terminal session as opposed to a notebook > session, I personally think some terminal output should be displayed > with various colours. Such colour output is a nice and easy way of > distinguishing different types of output. Say, the "sage: " prompt can > coloured using one colour, error and traceback messages can be > coloured using another colour, etc. What I have in mind is something > like what one would get with a Pari/GP terminal session. Here is such > a coloured session under Windows, in case you want a visual: > > http://mvngu.files.wordpress.com/2008/08/windows-session.png > > I recently had a meeting with a maths educator who is very interested > in using Sage for undergraduate maths and cryptography. The above > coloured output issue is one of his feature requests. > > -- > Regards > Minh Van Nguyen --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
Thank you for your help. I realize now how silly it has been to ask such a general question here, with you guys just guessing. Even this not being the solution, this has still been helpful for me to understand something more. Hopefully, I'll get more into it. By the way, any other comment about all the other facts? Thanks Maurizio On 19 Mar, 23:48, William Stein wrote: > On Thu, Mar 19, 2009 at 3:45 PM, Maurizio wrote: > > > Hi > > > can anyone give an advice on how to adapt Quantities to let it be > > compatible with SAGE? I don't know how SAGE modifies the way to > > represent numbers, and why it does not comply with Quantities. > > > For example, how does SAGE generate an instance of > > "sage.rings.integer.Integer"? I hope this can help me. Actually, I > > wasn't able to understand how Quantities deals with numbers, because > > it basically transform any python int or float multiplied by a > > Does Quantities have any code that looks like this: > > if isinstance(foo, (int, long)): > ... > > or anything remotely like that? If so, you just have to change it to > > int_types = (int, long, Integer) > if isistance(foo, int_types): > ... > > William > > > > > physical unit, into a numpy array (either a single element or a > > vector) with unit "dimensionless". I think there would be nothing > > wrong with continue using normal sage integers or float as > > dimensionless, even though I don't know how could we manage an object > > given by the multiplication of an integer and a physical unit: would > > this become a "quantity" instance? This would be fast to implement, > > because that's the way it is now. Nonetheless, this is not the way I > > would like it to do, because it would cause the necessity to add in > > quantity the way to deal with all the possible types in SAGE (also > > symbolics, in future?). > > > Is there any chance to do something like putting the physical quantity > > like a property of the existing numerical (and in future any other) > > class? I'm just wondering if is there any good way to do this, and if > > I would be able to try to work on that. > > > I've to admit, I'd like to be better in python programming, and to > > have more time to work on it. Until now, with a simple one-line > > modification, I has been able to let "quantities" accept the sum of > > coherent physical quantities, but I didn't manage to get the > > representation I was talking about on the previous post yet, > > especially because the "quantities" package is not really intended > > that way: the way I would have tried to produce something like that, > > is by distinguishing the units (e.g. Volts, Amperes, meters, ecc) from > > the multipliers (milli, micro, kilo, ecc) and then try to find a way > > to effectively combine them (in the expected way, like using the > > multipliers as a prefix to the unit: m+V = mV, centi+meter=cm, ecc). > > This seems more logical to me. > > > Another option, is to try to write this from scratch, trying to derive > > the most from others available packages out there (it's not really > > that much of lines of code), but I would not prefer to produce ANOTHER > > package about that! What do you think? > > I would prefer to keep that package, and simply try to apply some > > short differential patch to it to get a SAGE compatible version, but > > I'm not sure if I'll be able to. > > > Thank you for your time > > > Maurizio > > > On 16 Mar, 19:29, Maurizio wrote: > >> In fact my idea is a bit different, and I'll explain in a minute: > >> provided that the system is SI, you should get the result as a > >> multiplier (bigger than one) of the closest classic unit > >> representation > >> ex: meters -> nm - um - mm - m - km - ecc ecc > >> ex: > > >> x1 = 10cm > >> x2 = 1m > >> x1 + x2 = 1.1m > > >> y1 = 1V (Volt) > >> y2 = 0.5 V > >> y1 - y2 = 500 mV > > >> z1 = 500 mA [milliAmperes] > >> k = 3 > >> z1 * k = 1.5 A > > >> Does this looks reasonable? I find this very comfortable! > > >> Regarding imperial system, the same could be done, even though this is > >> just a bit tougher because of the fractional multipliers, but the > >> principle can stay the same. > > >> Two optional features could be very important, in my opinion: > >> 1) locking one object unit representation to a certain order of > >>
[sage-devel] Re: SAGE possible improvement
Hi
can anyone give an advice on how to adapt Quantities to let it be
compatible with SAGE? I don't know how SAGE modifies the way to
represent numbers, and why it does not comply with Quantities.
For example, how does SAGE generate an instance of
"sage.rings.integer.Integer"? I hope this can help me. Actually, I
wasn't able to understand how Quantities deals with numbers, because
it basically transform any python int or float multiplied by a
physical unit, into a numpy array (either a single element or a
vector) with unit "dimensionless". I think there would be nothing
wrong with continue using normal sage integers or float as
dimensionless, even though I don't know how could we manage an object
given by the multiplication of an integer and a physical unit: would
this become a "quantity" instance? This would be fast to implement,
because that's the way it is now. Nonetheless, this is not the way I
would like it to do, because it would cause the necessity to add in
quantity the way to deal with all the possible types in SAGE (also
symbolics, in future?).
Is there any chance to do something like putting the physical quantity
like a property of the existing numerical (and in future any other)
class? I'm just wondering if is there any good way to do this, and if
I would be able to try to work on that.
I've to admit, I'd like to be better in python programming, and to
have more time to work on it. Until now, with a simple one-line
modification, I has been able to let "quantities" accept the sum of
coherent physical quantities, but I didn't manage to get the
representation I was talking about on the previous post yet,
especially because the "quantities" package is not really intended
that way: the way I would have tried to produce something like that,
is by distinguishing the units (e.g. Volts, Amperes, meters, ecc) from
the multipliers (milli, micro, kilo, ecc) and then try to find a way
to effectively combine them (in the expected way, like using the
multipliers as a prefix to the unit: m+V = mV, centi+meter=cm, ecc).
This seems more logical to me.
Another option, is to try to write this from scratch, trying to derive
the most from others available packages out there (it's not really
that much of lines of code), but I would not prefer to produce ANOTHER
package about that! What do you think?
I would prefer to keep that package, and simply try to apply some
short differential patch to it to get a SAGE compatible version, but
I'm not sure if I'll be able to.
Thank you for your time
Maurizio
On 16 Mar, 19:29, Maurizio wrote:
> In fact my idea is a bit different, and I'll explain in a minute:
> provided that the system is SI, you should get the result as a
> multiplier (bigger than one) of the closest classic unit
> representation
> ex: meters -> nm - um - mm - m - km - ecc ecc
> ex:
>
> x1 = 10cm
> x2 = 1m
> x1 + x2 = 1.1m
>
> y1 = 1V (Volt)
> y2 = 0.5 V
> y1 - y2 = 500 mV
>
> z1 = 500 mA [milliAmperes]
> k = 3
> z1 * k = 1.5 A
>
> Does this looks reasonable? I find this very comfortable!
>
> Regarding imperial system, the same could be done, even though this is
> just a bit tougher because of the fractional multipliers, but the
> principle can stay the same.
>
> Two optional features could be very important, in my opinion:
> 1) locking one object unit representation to a certain order of
> magnitude and/or metric system
>
> ex:
> x1 = 1 cm
> x1.lock('cm')
> x2 = x1 + 1 m [x2 can inherit the lock property]
> x2 = 101 cm
> x2.lock('inches')
> x2 = 39.76 inches
> x2.unlock()
> x2 = 1.01 m
>
> PS: locking property could also be specified when instantiating an
> object
>
> 2) changing the standard metric system (imperial / SI / any other) so
> that by default each value is scaled as previously proposed
>
> Any comment?
>
> Thanks
>
> Maurizio
>
> On 16 Mar, 16:06, Robert Dodier wrote:
>
> > Maurizio wrote:
> > > Regarding the output of such expression you wrote, I agree that it
> > > should give a standard unit output for each physical quantity, so by
> > > presetting SI (or imperial, or anything else), it should give just
> > > meters (or feets, or anything else)...
>
> > I'm pretty sure that would cause more trouble than it's worth.
> > Whatever the standard, there could well be nonstandard combinations
> > such as centimeters per day or liters per kilometer, which should
> > be preserved as such. In the US, which is an important enough
> > audience to be accomodated in the design of a units package,
> > mixed-up units from different standards or no standards at all are
>
[sage-devel] Re: notebook share button
You are so kind in asking me this! Well, I find that labels are SO beautiful and powerful, especially something like the way gmail let us use them. I agree that probably a label system, incorporated with an efficient search method (or filtering) would probably be even better to use and (maybe) easier to implement than folders. Thank you very much!! By the way, kudos for the good job, and congratulations for the Sun article, you are certainly deserving to gain popularity! PS: I still encourage you to improve engineering features ;) On 19 Mar, 22:19, William Stein wrote: > On Thu, Mar 19, 2009 at 2:14 PM, Maurizio wrote: > > > I know this is not being polite from me, but would you also consider > > implementing folders in SAGE notebook? > > > I would really appreciate, since the number of my notebooks is growing > > fast, and I'm wondering how you guys are managing it, maybe the > > feature it's already there and I don't know about it. > > Thanks for the feature request. That feature is *not* there, and yes, > we definitely need to implement it. > > Would you be OK with labels instead of folders? I.e., you could > attach any number of labels to each worksheet, and easily see a list > of all worksheets with a given label? I personally find labels more > flexible than folders (since a worksheet can have multiple labels), > and I think they're also easier to implement. > > -- William --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: notebook share button
I know this is not being polite from me, but would you also consider implementing folders in SAGE notebook? I would really appreciate, since the number of my notebooks is growing fast, and I'm wondering how you guys are managing it, maybe the feature it's already there and I don't know about it. Thanks Maurizio On 19 Mar, 22:05, William Stein wrote: > Hi, > > I implementing the feature in the notebook before where it lists all > users when you click on "Share". I thought this was nice, since you > could chose the ones you want. There are now 6598 users at > sagenb.org, which makes the share button nearly useless. Are people > OK with us changing "share" so it doesn't list any other usernames? > It would of course be an easy one-line patch. > > William > > -- > William Stein > Associate Professor of Mathematics > University of Washingtonhttp://wstein.org --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
In fact my idea is a bit different, and I'll explain in a minute:
provided that the system is SI, you should get the result as a
multiplier (bigger than one) of the closest classic unit
representation
ex: meters -> nm - um - mm - m - km - ecc ecc
ex:
x1 = 10cm
x2 = 1m
x1 + x2 = 1.1m
y1 = 1V (Volt)
y2 = 0.5 V
y1 - y2 = 500 mV
z1 = 500 mA [milliAmperes]
k = 3
z1 * k = 1.5 A
Does this looks reasonable? I find this very comfortable!
Regarding imperial system, the same could be done, even though this is
just a bit tougher because of the fractional multipliers, but the
principle can stay the same.
Two optional features could be very important, in my opinion:
1) locking one object unit representation to a certain order of
magnitude and/or metric system
ex:
x1 = 1 cm
x1.lock('cm')
x2 = x1 + 1 m [x2 can inherit the lock property]
x2 = 101 cm
x2.lock('inches')
x2 = 39.76 inches
x2.unlock()
x2 = 1.01 m
PS: locking property could also be specified when instantiating an
object
2) changing the standard metric system (imperial / SI / any other) so
that by default each value is scaled as previously proposed
Any comment?
Thanks
Maurizio
On 16 Mar, 16:06, Robert Dodier wrote:
> Maurizio wrote:
> > Regarding the output of such expression you wrote, I agree that it
> > should give a standard unit output for each physical quantity, so by
> > presetting SI (or imperial, or anything else), it should give just
> > meters (or feets, or anything else)...
>
> I'm pretty sure that would cause more trouble than it's worth.
> Whatever the standard, there could well be nonstandard combinations
> such as centimeters per day or liters per kilometer, which should
> be preserved as such. In the US, which is an important enough
> audience to be accomodated in the design of a units package,
> mixed-up units from different standards or no standards at all are
> very common, and should be preserved as such.
> And whatever the system or lack of it, it would be annoying to
> change fractional or multiple units (inches, kilometers, etc) to
> their base units (feet, meters, etc).
>
> The point is to accomodate the user, who has a better idea about
> what they want to accomplish than the package writer.
>
> FWIW
>
> Robert Dodier
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[sage-devel] Re: SAGE possible improvement
Hi Fergus, thank you for your comments! So, do you consider working on a Quantity porting worthwhile? It seems that you got some good experience by working on it, so you can probably give some better advice about the structure of that package. Moreover, I'm wondering how much work would it require to try to allow symbolic support for SAGE for Quantities or any other units package. Regarding the output of such expression you wrote, I agree that it should give a standard unit output for each physical quantity, so by presetting SI (or imperial, or anything else), it should give just meters (or feets, or anything else)... Regards Maurizio On 16 Mar, 00:55, "fergusno...@gmail.com" wrote: > Hi, > > Thanks for emailing me Nicolas. > > I had a quick play with writing a units extension really just to learn > more about SAGE. I've only just started writing this so its still a > way off being ready for prime time but so far you can create > quantities with units, manipulate them like any other number and > convert to different units. There is also a sub-library of common > physical constants with units. > > I hadn't heard of the Quantity package until just now but it looks > much more mature than what I have been working on. I took a slightly > different approach in that in my code quantities are always kept in SI > base units so simplification is never necessary but that means that > sometimes it makes assumptions about what units the user would like > the results in e.g. > > (10 * meter)**3 / (5 * ft)**2 > > will give 40 m**3/ft**2 in Quantity as it is unclear whether the user > wants the result in meters or feet and the user must explicitly > simplify the result to the unit they wanted, whereas in my code will > always output in meters and the user can convert it to feet if needed. > This also means you can add dissimilar units of the same > dimensionality and the result will just end up in SI units. > > I will clean up my code and make a little demo so people can play with > it when I have a bit more free time on tuesday, if anyone is > interested. I'm still keen to keep developing my implementation but I > can see that porting Quantity to work with SAGE might be a quicker way > to get a mature units system up and running. > > Thanks, > Fergus --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
two Enthought package, although this units mixing (claimed as possible in Enthought) seems not natively supported (if I try to add 10 inches and 10 meters I get an error... I can't even add meters and centimeters!) which is not good. A good plus about "quantities" is that it seems actively developed, as I can see from their active mailing list: https://lists.launchpad.net/python-quantities-developers/threads.html I can see that in the middle of January they were thinking about their timeline, since they presented something to the SciPy community recently, and had some good feedback. They are currently discussing about being almost ready to present something to the numpy community, so they seems satisfied with what they have now: https://lists.launchpad.net/python-quantities-developers/msg00057.html Don't you think it would be REALLY useful for us to try to discuss with them (I'm sure some of you guys, can represent this SAGE community much better than I do), and to ask them if they are willing to work with us on making quantities compatible with one of our symbolic packages? They seem pretty experienced about this package, seem willing to improve their work, and this is (in my opinion) going to be a VERY BIG PLUS for SAGE!! I mean, I don't think anything out there is actually able to manage symbolics and units at the same time, do you? I'm very eager to see your comments, hoping that you get my passion and enthusiasm! Best regards Maurizio --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE possible improvement
Thank you Jason, I'll try it as soon as possible. By the way, have you got any idea about where in the code should I look at to let it work with SAGE numbers? Something like constructors or stuff like that? Thanks Maurizio On 15 Mar, 02:29, Jason Grout wrote: > Maurizio wrote: > > To be honest, I'd have thought that installing a python package and > > let it work with SAGE would have been easier, but one issue could be > > that I've been working on this in a Saturday night (after coming back > > home) from midnight to 1.30 am!! :) > > > I summarize the way I got "quantities" (http://pypi.python.org/pypi/ > > quantities) installed at the end (consider I'm using a VMWare virtual > > machine from XP): > > 1. login as manage > > 2. sudo su > > 3. type sage -sh to go into the sage environment > > 4. unpack and install quantities > > 5. run SAGE and python and test > > > The first test failed. I mean, I got it installed and running: > > 1) unpack the quantities-0.5b2.tar.gz > > 2) python setup.py install > > > The result is not satisfying me: > > > 1) if I run python from that sage -sh shell, I can use quantities in > > the same way they show in the tutorial (http://packages.python.org/ > > quantities/user/tutorial.html). They seem to clearly claim that > > quantities is still in an advanced beta development phase, so it's not > > fully documented, nor available for production (yet). > > I can confirm, the documentation seems missing: example > > > import quantities as pq > > pq.Quantity? > > > File: /usr/local/sage/local/lib/python2.5/site-packages/ > > quantities-0.5b2-py2.5.egg/quantities/quantity.py > > Type: > > Definition: pq.Quantity( [noargspec] ) > > Docstring: > > x.__init__(...) initializes x; see x.__class__.__doc__ for signature > > > That's it! Seems poor... > > > 2) The biggest issue is that I can't get it to work within a SAGE > > notebook: > > > from numpy import * > > import quantities as pq > > res = 10*pq.ohm > > > Traceback (click to the left for traceback) > > ... > > TypeError: unsupported operand parent(s) for '*': 'Integer Ring' and > > '' > > It sounds like the problems is the known issue that numpy does not > interact very well with Sage data types. Try this: > > from numpy import * > import quantities as pq > res = 10r*pq.ohm > > The 10r means to create a python integer, rather than a Sage integer. > > It sounds like there could/should be a small change in quantities made > to support Sage datatypes. My guess is that it would take just a few > minutes. > > Jason > > > > > I'm really not that good with all this stuff, but my understanding is > > that, whenever you try to define a new object like an integer or a > > float number times a "quantities" unit, it somehow forces the number > > to become a numpy array. This seems to fail within a SAGE notebook. > > > Any idea on how this could be fixed, or otherwise should be not? > > I am just talking out of couple of minutes working on it, I admit it. > > > Anyway, I'll try to get the other packages installed as well, although > > I am not sure when. Any other suggestion or comment is very well > > accepted! > > > Final comment: should I have done any other sage command to let it > > reload or synchronize the newly installed sage packages, before > > running the notebook? > > > Thank you > > > Maurizio > > > Maurizio > > > On 14 Mar, 09:21, Jason Grout wrote: > >> Maurizio wrote: > >>> Hello, > >>> I'm forwarding this to sage-devel as well, maybe being the most > >>> appropriate group to address this issue. > >>> I'm a happy user of SAGE, and I won't stop thanking all you guys for > >>> this wonderful job! Although, I also try to encourage you in getting > >>> something better (from my point of view). > >>> It seems there has been some serious thinking about including a UNITS > >>> of MEASUREMENTS managing package in SAGE: > >>>http://groups.google.com/group/sage-devel/browse_frm/thread/8791448b7... > >>> From this, a SAGE trac ticket has been opened (#3852): > >>>http://trac.sagemath.org/sage_trac/ticket/3852 > >>> This is supposed to be a MAJOR priority ticket, and I think this is a > >>> very appropriate description! > >> I agree. I should also add that nearly every ticket in trac is marked > &g
[sage-devel] Re: SAGE possible improvement
Does he keep track of his experiment somewhere on the net? I would like to have a look at it. By the way, this effort is certainly good, but one of the biggest merit of SAGE was (in my modest opinion) the idea to not reinvent the wheel as long as it's possible. (I hope SAGE is not changing its path, in reimplementing basics in its own way...) So, in this case I can see that the "unit of measurements" package shouldn't be too much of effort to build one from scratch, so trying to adapt an existing one to work with SAGE couldn't be the best choice in this case, nonetheless I am wondering if the other opportunities out there (there are at least three, as you can see in the trac ticket) have been previously explored to take some advantage! There are non-trivial issues like compound units management that may have already been successfully faced. Regards Maurizio > > By the way, fergusnoble on IRC was working on a units package for Sage > a few days ago. Unfortunately, I don't know his email address, but > Nicolas Thiery does. > > Carl --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
