[sage-devel] Cubic to Weierstrass
Andrey, The bundle probably would not be of much use to you, since the function takes as input a Sage multivariate polynomial ring element and outputs a Sage elliptic curve over some field, when all you want is symbolic expression in Weierstrass normal form. Do you have a copy of the implementation of Nagell's algorithm that you were using? I'm curious as to what is taking so long, since there aren't very many complicated steps; it's mostly basic arithmetic. -Bobby On Thu, May 22, 2008 at 1:11 PM, William Stein [EMAIL PROTECTED] wrote: Andrey, Check out the hg bundle attached to this ticket: http://trac.sagemath.org/sage_trac/ticket/1136 Bobby Moretti was implementing code for doing this transformation, but never finished due to a subtle bug in the transformation maps (he gets the right cubic but not the right maps). It's possible you'll find the above bundle useful (no clue). On Thu, May 22, 2008 at 1:04 PM, Andrey Novoseltsev [EMAIL PROTECTED] wrote: I tried to convert 2*x*y^2 + 2*a5*t*x*y - x^2 + (2*a4 - 8*t^3)*x - 1, where a4, a5, and t are some complex parameters (which I would like to keep as undetermined parameters), to Weierstrass normal form using Nagell's algorithm and was not quite successful since some steps near the end do not finish in a reasonable time (i.e. a few minutes). It is possible that I have done some mistakes, since I didn't really tested my code yet, but Jacob Lewis told me that this algorithm isn't very fast anyway. As far as I can tell, Sage can do this conversion using MAGMA, but only over rational field. Can anyone recommend an efficient way of doing such a conversion with symbolic coefficients? Or, perhaps, it is already done and I just cannot find the proper function? Thank you! Andrey -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- Bobby Moretti [EMAIL PROTECTED] -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Sage 2.10.2.alpha2 released
On Wed, Feb 20, 2008 at 8:57 PM, [EMAIL PROTECTED] wrote: ??? Either I've got a doppelganger, I've been fixing Sage bugs in my sleep, or this was misattributed... You mean you haven't seen my long red braided hair? :) -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-devel] Re: Fwd: blog and rss
This error seems to be due to the python install that you're using. [EMAIL PROTECTED]: which python /usr/local/bin/python It seems to get past this step if you do: /usr/bin/python /home/yqiang/planet/planet.py /home/yqiang/planetsage/fancy/config.ini the python interpreter at /usr/bin/python is only python 2.4, but who cares. You're only going to run this from a cron job periodically, correct? On Dec 10, 2007 1:07 PM, Yi Qiang [EMAIL PROTECTED] wrote: I would say that unless you are really serious about blogging, using hosted blogging is even easier. Try blogspot (http://www.blogspot.com). As for setting up planet.sagemath.org, I tried to set it up on sage.math.washington.edu last night but ran into this problem: In [1]: import bsddb --- type 'exceptions.ImportError' Traceback (most recent call last) /home/yqiang/ipython console in module() /home/was/s/local/lib/python2.5/bsddb/__init__.py in module() 49 from bsddb3.dbutils import DeadlockWrap as _DeadlockWrap 50 else: --- 51 import _bsddb 52 from bsddb.dbutils import DeadlockWrap as _DeadlockWrap 53 except ImportError: type 'exceptions.ImportError': libdb-4.1.so: cannot open shared object file: No such file or directory The planetplanet software requires the bsddb module. Maybe someone with more knowledge can resolve that issue on sage.math.washington.edu. On Dec 10, 2007 12:53 PM, Bobby Moretti [EMAIL PROTECTED] wrote: I think there are two steps: 1) start a blog - wordpress is frickin' easy to set up. For that, you'd go to http://wordpress.org/download/ - grab the software, untar, set up apache to serve the directory (so perhaps you would want something like http://wstein.org/blog) - pt-get install mysql and php. - follow the instructions here: http://codex.wordpress.org/Installing_WordPress#Famous_5-Minute_Install 2) set up planet.sagemath.org - I'm not so knowledgeable about this one, but the instructions look pretty straightforward, and it's written in python. On Dec 10, 2007 12:18 PM, William Stein [EMAIL PROTECTED] wrote: On Dec 10, 2007 12:15 PM, Ondrej Certik [EMAIL PROTECTED] wrote: On Dec 10, 2007 8:07 PM, Bobby Moretti [EMAIL PROTECTED] wrote: Very cool. Now I just need to find time to blog! :) And that's exactly the point of the planet, you don't have to find time to blog regularly. If there are enough people on it, and if the atmosphere is that they mark by sage only post about Sage and not some stupid things, then planet always contains some interesting info, and it's really cool to read it as a user. Hi, Could somebody post trivial steps so I can -- in a manner of moments -- go from somebody who has never written a blog post to somebody who is writing a blog post that appears on some sort of Planet Sage? I'm sure I could write a little something about the slashdotting this weekend, status of sage, etc I bet there are a few other people out there in the audience that would similarly like to follow such directions. -- Willam -- Bobby Moretti [EMAIL PROTECTED] -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Fwd: blog and rss
I think there are two steps: 1) start a blog - wordpress is frickin' easy to set up. For that, you'd go to http://wordpress.org/download/ - grab the software, untar, set up apache to serve the directory (so perhaps you would want something like http://wstein.org/blog) - pt-get install mysql and php. - follow the instructions here: http://codex.wordpress.org/Installing_WordPress#Famous_5-Minute_Install 2) set up planet.sagemath.org - I'm not so knowledgeable about this one, but the instructions look pretty straightforward, and it's written in python. On Dec 10, 2007 12:18 PM, William Stein [EMAIL PROTECTED] wrote: On Dec 10, 2007 12:15 PM, Ondrej Certik [EMAIL PROTECTED] wrote: On Dec 10, 2007 8:07 PM, Bobby Moretti [EMAIL PROTECTED] wrote: Very cool. Now I just need to find time to blog! :) And that's exactly the point of the planet, you don't have to find time to blog regularly. If there are enough people on it, and if the atmosphere is that they mark by sage only post about Sage and not some stupid things, then planet always contains some interesting info, and it's really cool to read it as a user. Hi, Could somebody post trivial steps so I can -- in a manner of moments -- go from somebody who has never written a blog post to somebody who is writing a blog post that appears on some sort of Planet Sage? I'm sure I could write a little something about the slashdotting this weekend, status of sage, etc I bet there are a few other people out there in the audience that would similarly like to follow such directions. -- Willam -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Fwd: blog and rss
If I had a blog, and signed up its RSS feed to planetsage, would *all* my posts be visible, or could I filter posts based on a tag? For example, the second post on planet gnome right now is about Dennis Kucinitch... -Bobby On Dec 9, 2007 10:55 AM, Yi Qiang [EMAIL PROTECTED] wrote: Ok, there seems to be enough interest for this idea. I think the next step will be actually finding out HOW many of us blog, or would be willing to start blogging about SAGE. http://wiki.sagemath.org/planetsage Please go there and put a link to your blog if you have one, or make an entry saying you are interested in starting a blog. Cheers, Yi http://yiqiang.org On Dec 9, 2007 3:49 AM, Robert Bradshaw [EMAIL PROTECTED] wrote: +1 to the planet.sagemath.org idea, including official blog with release announcements, bug and Sage days info, etc. A semi-official, regular (weekly? authorship could rotate) tips and tricks blog could be good too, and another idea would be a regular How do I ___ in Sage which could take email submissions. From a marketing standpoint, I think regularity is an important thing, like newspaper columns and TV shows (you want people to keep coming back because they know there's going to be something new and then anticipate it.) It could grow into a large resource of examples too (and maybe even get doctested?) Of course, this could turn out to be a significant time investment (though the latter could be largely fleshed-out responses to sage- support). Robert On Dec 8, 2007, at 10:04 PM, Ondrej Certik wrote: Yes, I was just going to say the same thing. planet.sagemath.org is the way to go. Besides developers blogs, there can also be an official blog (with several core sage developers having a write access to), where official things will be announced. Its true, that writing a blog requires time, but it's worthy and necessary. Ondrej On 12/9/07, alex clemesha [EMAIL PROTECTED] wrote: On Dec 8, 2007 8:09 PM, Yi Qiang [EMAIL PROTECTED] wrote: Actually, depending on how many SAGE developers blog at all, we should consider a planet.sagemath.org style blog. The idea is the planet.* is an aggregator of blogs it subscribes to and publishes blogs with specific tags. For example, planet.sagemath.org would subscribe to Mike Hanson, Martin Albrecht, and Ondrej Certik's blog. Each time those people post something to their own blogs with the 'sage' tag, it will show up on planet.sagemath.org. Many open source communities use this. See the urls below for examples. The software that makes it happen is called PlanetPlanet (http://www.planetplanet.org/) Some projects that use this include: * Planet GNOME (planet.gnome.org) * Planet Debian (planet.debian.org) * Planet Twisted (planet.twistedmatrix.org) etc..You can see a more complete list at planetplanet.org. Hey Yi, that's a really good idea. Even Python has their own planet: planet.python.org and on the side bar of that page there is a link to a bunch more planets ... basically there's a lot of gravity to this idea ;) Alex On Dec 8, 2007 7:05 PM, William Stein [EMAIL PROTECTED] wrote: On Dec 8, 2007 7:03 PM, Bobby Moretti [EMAIL PROTECTED] wrote: At the very least, I think it would be a good idea to use a content management system for the website. That's a really good idea. Mike Hansen has been getting really into Django lately, so maybe he can help with that. Using Django would probably make a lot of sense. The front page could be blog-like, containing mostly news, updates, info, and releases. Yep. Then if someone has a personal blog entry that says something interesting about Sage, we can just link to it from the front page as a news story. This way everything would be archived, etc. I like this idea. William On Dec 8, 2007 6:59 PM, didier deshommes [EMAIL PROTECTED] wrote: 2007/12/8, William Stein [EMAIL PROTECTED]: Hi, My brother suggests that a Sage blog be somehow created (see below). It's a good idea. Any ideas about what this might entail? Weekly developer summaries? A cool trick? Little articles? Etc. I have never blogged +1 This could also be good to announce new versions, improvements, papers written in Sage, etc. Developers blogging about Sage could be fun: it would expose how some other parts of the Sage code works (this would also help Bus Days). For example, when I wrote QDRF, I blogged about what one would need to do in order to implement (floating-point) fields in Sage since I had learned a great deal about this part of the code. Of course, the thing with blogging is time :) . If you're blogging, you're not writing code
[sage-devel] Re: Fwd: blog and rss
At the very least, I think it would be a good idea to use a content management system for the website. The front page could be blog-like, containing mostly news, updates, info, and releases. Then if someone has a personal blog entry that says something interesting about Sage, we can just link to it from the front page as a news story. This way everything would be archived, etc. -Bobby On Dec 8, 2007 6:59 PM, didier deshommes [EMAIL PROTECTED] wrote: 2007/12/8, William Stein [EMAIL PROTECTED]: Hi, My brother suggests that a Sage blog be somehow created (see below). It's a good idea. Any ideas about what this might entail? Weekly developer summaries? A cool trick? Little articles? Etc. I have never blogged +1 This could also be good to announce new versions, improvements, papers written in Sage, etc. Developers blogging about Sage could be fun: it would expose how some other parts of the Sage code works (this would also help Bus Days). For example, when I wrote QDRF, I blogged about what one would need to do in order to implement (floating-point) fields in Sage since I had learned a great deal about this part of the code. Of course, the thing with blogging is time :) . If you're blogging, you're not writing code and sometimes you just can't afford that ;). didier at all, but I know some of you (e.g., Martin Albrecht and Ondrej Certik) are old pros at blogging. Thoughts? -- Forwarded message -- From: Dennis Stein [EMAIL PROTECTED] Date: Dec 8, 2007 1:28 PM Subject: blog and rss To: William Stein [EMAIL PROTECTED] William, Non-developer users of Sage might enjoy learning more about what is going on in the Sage world. A blog would be a great way to do this. You could post things like the AMS event, published articles, news of major changes in the software, upcoming cool new features, something funny that is Sage related, a profile of someone who has significantly contributed to the software, a user profile, and so on. People could subscribe to it via email or RSS. You could use a free blog service (webpress or blogspot or whatever) and use Google's free Feebburner for the email subscription service for people to subscribe. http://www.mathworks.com/company/rss/index.html Google has a blog that they post to about once every three weeks or so. Obviously making the software the best it can be is a bigger priority, but a blog could be useful at some point for keeping in touch with people (reporters, users, fans). --Dennis -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: My talk with martin Albrecht
A typo: on page 11, replace permutations groups with permutation groups. On page 38, you say #sage-devel. You might also want to give the irc server's address. Looks like a great intro to Sage. Good luck with the talk. -Bobby On Nov 9, 2007 4:17 PM, William Stein [EMAIL PROTECTED] wrote: Hi everybody, The slides of Martin and my talk are available at http://sage.math.washington.edu/tmp/talk/. An accompanying SAGE worksheet can be found at http://sage.math.washington.edu/home/malb/SAGE_Demo.sws . Feedback is very welcome :-) William -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Issue during upgrade
-- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Issue during upgrade
Sorry, accidentally hit send before I wrote anything :). When upgrading to 2.8.9, the upgrade halts with the output /bin/sed: can't read /home/bob/sage-2.8.7/local/lib/libgmp.la: No such file or directory I renamed the directory /home/bob/sage-2.8.7 to /home/bob/sage. Something in sage -upgrade seems to be depending the hardcoded absolute path. (This is while installing libfplll) The temporary fix was to symlink ~/sage-2.8.7 to ~/sage. -Bobby On 10/28/07, Bobby Moretti [EMAIL PROTECTED] wrote: -- Bobby Moretti [EMAIL PROTECTED] -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: posible licence issue raised by GPL-v3
On 7/29/07, Alec Mihailovs [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] Not always so. Verbatim snippet from the horse's mouth: When we say that GPLv2 and GPLv3 are incompatible, it means there is no legal way to combine code under GPLv2 with code under GPLv3 in a single program. This is because both GPLv2 and GPLv3 are copyleft licenses: each of them says, If you include code under this license in a larger program, the larger program must be under this license too. There is no way to make them compatible. We could add a GPLv2-compatibility clause to GPLv3, but it wouldn't do the job, because GPLv2 would need a similar clause. Fortunately, license incompatibility only matters when you want to link, merge or combine code from two different programs into a single program. There is no problem in having GPLv3-covered and GPLv2-covered programs side by side in an operating system. For instance, the TeX license and the Apache license are incompatible with GPLv2, but that doesn't stop us from running TeX and Apache in the same system with Linux, Bash and GCC. This is because they are all separate programs. Likewise, if Bash and GCC move to GPLv3, while Linux remains under GPLv2, there is no conflict. http://www.gnu.org/licenses/rms-why-gplv3.html Well, I wouldn't call SAGE a single program. The issue is complicated, and I doubt a lawyer would agree. Besides, that's exactly what commercial CAS's do. In particular, Maple includes gmp and a series of other programs under separate licenses. gmp is licensed under the GNU LGPL, which is GPL without the linking requirements, so Maple can do what they want, as long as they don't modify GMP. If they modify GMP, then they have to publish their changes under the LGPL, but they can leave the maple core alone. Alec -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: posible licence issue raised by GPL-v3
On 7/29/07, Justin C. Walker [EMAIL PROTECTED] wrote: On Jul 29, 2007, at 18:24 , Alec Mihailovs wrote: From: [EMAIL PROTECTED] Not always so. Verbatim snippet from the horse's mouth: When we say that GPLv2 and GPLv3 are incompatible, it means there is no legal way to combine code under GPLv2 with code under GPLv3 in a single program. This is because both GPLv2 and GPLv3 are copyleft licenses: each of them says, If you include code under this license in a larger program, the larger program must be under this license too. There is no way to make them compatible. We could add a GPLv2-compatibility clause to GPLv3, but it wouldn't do the job, because GPLv2 would need a similar clause. Fortunately, license incompatibility only matters when you want to link, merge or combine code from two different programs into a single program. There is no problem in having GPLv3-covered and GPLv2-covered programs side by side in an operating system. For instance, the TeX license and the Apache license are incompatible with GPLv2, but that doesn't stop us from running TeX and Apache in the same system with Linux, Bash and GCC. This is because they are all separate programs. Likewise, if Bash and GCC move to GPLv3, while Linux remains under GPLv2, there is no conflict. http://www.gnu.org/licenses/rms-why-gplv3.html Well, I wouldn't call SAGE a single program. Besides, that's exactly what commercial CAS's do. In particular, Maple includes gmp and a series of other programs under separate licenses. Isn't 'gmp' a library, rather than a program? One of the GPL issues for those producing non-GPL'd code is that of libraries: some GPL'd libraries can be included without poisoning the program's licensing, while others can not. I think it's much worse under the GPL3 umbrella. GMP is licensed under the LGPL (which used to be called the Library GPL, but was retroactively named Lesser GPL due to confusion). However, anything that is licensed under the normal GPL cannot be linked without infecting the main program, be it a library, program, snippet of code, etc... See http://clisp.cvs.sourceforge.net/*checkout*/clisp/clisp/doc/Why-CLISP-is-under-GPL for more details on this. As far as I know, GPLv3 doesn't really affect this property of the license. The main difference is that GPLv3 will prevent you from making your own modifications to a GPLv3'd program, releasing the source, but then ensuring (through a digital signature scheme) that it cannot run on the hardware you distributed it with. -Bobby Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Absorption of Federal Funds If you're not confused, You're not paying attention -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: posible licence issue raised by GPL-v3
On 7/29/07, Alec Mihailovs [EMAIL PROTECTED] wrote: From: Bobby Moretti [EMAIL PROTECTED] Well, I wouldn't call SAGE a single program. The issue is complicated, and I doubt a lawyer would agree. Besides, that's exactly what commercial CAS's do. In particular, Maple includes gmp and a series of other programs under separate licenses. gmp is licensed under the GNU LGPL, which is GPL without the linking requirements, so Maple can do what they want, as long as they don't modify GMP. If they modify GMP, then they have to publish their changes under the LGPL, but they can leave the maple core alone. I agree that including gmp in Maple wasn't a good example. Nevertheless, SAGE AFAICT is a distribution of various programs rather than a single program. Something like, say, TEX Live, that doesn't have a single license, see http://www.tug.org/texlive/LICENSE.TL It would be one thing if SAGE was just a distribution of software, with a package management system. But SAGE contains (lots) of code that wraps these libraries and provides a unified interface to them. I'm fairly confident that this falls under the GPL's concept of 'linking'. Alec -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: SAGE Documentation brainstorming
The SAGE wiki: http://www.sagemath.org:9001/ There is a link from the main page. MoinMoin with SAGE supports LaTeX. -Bobby On 7/25/07, Chris Chiasson [EMAIL PROTECTED] wrote: Is conversion to LaTeX a requirement or merely a nice-to-have? On Jul 25, 1:16 pm, Timothy Clemans [EMAIL PROTECTED] wrote: That is already available by creating Wiki-books. Wiki-books can not be easily converted to LaTeX documents.http://en.wikibooks.org On 7/25/07, Chris Chiasson [EMAIL PROTECTED] wrote: Someone has to be evil and mention this: MediaWiki If you are willing to sacrifice absolute editorial control, the wiki documentation can develop organically at its own pace and in the manner that the writers choose. There is already a site that wove together Mathematica and MediaWiki. The same could probably be done for SAGE. Of course, that site hasn't done so well because the Mathematica user base is so small and the pre- existing documentation for Mathematica nullifies much pf the possible benefit of the wiki. Not to mention that MMA 6 broke the site... Doesn't MediaWiki already support some TeX/LaTeX? On Jul 22, 8:41 pm, William Stein [EMAIL PROTECTED] wrote: Hello, I think SAGE might potentially greatly benefit from certain types of new documentation. Unfortunately, after consider a number of possibilities, I'm unsure about how to proceed. I'll discuss the best idea Josh Kantor and I came up with below. Let me know what you think, or suggest something else if you have any other ideas, or let me know what your concerns are (or if you would like to volunteer some writing). We could create a new manual, similar in format to the SAGE Tutorial, SAGE Reference manual, etc., but instead entitled SAGE Overview. This latex document might have chapters entitled as follows, and primary contributors as listed to the right: * Calculus -- me, Bobby Moretti, ?? * Combinatorics -- Robert Miller, Emily Kirkman * Algebra -- Martin Albrecht, David Joyner * Number Theory -- William Stein, Jaap Spies, David Kohel * Linear Algebra -- Josh Kantor, Robert Bradshaw, William Stein * Numerical Computation -- Josh Kantor * Plotting -- Tom Boothby, Josh Kantor, Me, Alex Clemesha Each chapter would have a few paragraphs that overview what one can do in SAGE related to each topic, followed by sections that go into more detail with examples. This is probably a very rough prototype of the sort of information the numerical computation chapter might provide: http://www.math.washington.edu/~jkantor/C_Fortran/C_Fortran.html The idea is that if you're a new users to SAGE, after getting some very basic feeling for SAGE, you flip directly to the relevant chapter of the book *for you*, e.g., if you do algebra you read that chapter, if you do calculus you read the calculus chapter, etc. And in reading that chapter, you get a pretty good sense of what SAGE is capable in your specialty, where to find further documentation (e.g., when you read about number theory, you learn that SAGE includes NTL, that NTL can do blah, and that you can find out more at location xyz). Also, there are some (but not too many) doctested examples throughout. What do people think? People would contribute to this document using hg_doc patches, just like they do now with tutorial, etc., contributions. An alternative would be to create short books for each topical area. This might be more manageable, or it might be less manageable; I'm not sure. -- William Stein Associate Professor of Mathematics University of Washingtonhttp://www.williamstein.org -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: predefined symbolic variable names
Hi all,
So far I've been refraining from posting here, since I don't have
strong feelings one way or the other, but the discussion so far has
been great and I'd like to leave a few comments.
On 7/8/07, William Stein [EMAIL PROTECTED] wrote:
Hi,
Thanks for all the feedback from everybody about symbolic variables,
special functions, etc. For now (i.e., the very near term), I think
the best thing to do is:
(1) remove all predefined *symbolic* variables except x,
leave in e, pi, and I:
-- everybody basically wants this.
This is fine. I'm not sure which approach is better. There will be
lots of Maple/Mathematica users who will find it bizarre that they
have to manually declare their variables, but I guess there's nothing
wrong with that.
(2) don't make any changes to how special functions behave.
-- doesn't seem necessary.
I agree. RR(expr) is very easy to use. As is float(expr).
(3) don't make any changes to how floating point literals behave.
-- basically put making any changes here on hold, since
substantial discussion still hasn't revealed a
sufficiently good solution.
If one wants purely C-library float special functions,
doing, e.g.,
from math import sin, cos, tan
etc., works very well right now. And using float(2.5) or 2.5r
works fine now.
Agreed.
I'm intrigued by Marshall's remark about What I think is bad is
that something like 1.0*sin(1) is not numerical - in mathematica
the sin(1) would be forced into a numerical type.
Here's what Maxima/Mathematica/Maple/Mupad do:
sage: maxima.eval('2.5*sin(1)')
'2.5*sin(1)'
sage: mathematica.eval('2.5*Sin[1]')
2.10368
sage: maple.eval('2.5*sin(1)')
'2.5*sin(1)'
sage: mupad.eval('2.5*sin(1)')
2.5 sin(1)
Here's what SAGE does:
sage: 2.5*sin(1)
2.50*sin(1)
Here's what REDUCE does -- which is totally different
(and nuts, IMHO):
1: 2.5*sin(1);
5*sin(1)
--
2
So Mathematica is in fact the only system that makes sin(1)
symbolic but 2.5*sin(1) numerical. I.e., Maple, SAGE, Mupad,
and Reduce all tend toward 2.5*sin(1) being as symbolic as
possible for some reason.
From an implementation point of view, given the SAGE rules,
it makes way more sense for 2.5*sin(1) to remain symbolic,
since:
(1) this is what the backend simplification system (maxima) does,
and
(2) 2.5 * sin(1) in SAGE is computed by making 2.5 symbolic,
then doing the multiply formally.
I'm not saying we shouldn't find a way to make 2.5 * sin(1) possibly
be numerical. I'm just remarking that this is a complicated issue
and it definitely deserves further discussion.
I actually really like Mathematica's behavior on this one. I think
it's worth considering. From a pragmatic point of view, it seems to me
that if I'm multiplying something symbolic by something approximate, I
don't want to see anything symbolic in the result, since my result is
inherently limited by the approximation. It's less clear in the case
of addition.
I think ultimately we will need to get feedback from a broader group
of users. What we as developers think is best might not actually
correspond to what most people who will be using SAGE want and expect.
~Bobby
-- William
--
Bobby Moretti
[EMAIL PROTECTED]
--~--~-~--~~~---~--~~
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[sage-devel] Re: Symbolic manipulation questions
On 6/1/07, Joel B. Mohler [EMAIL PROTECTED] wrote:
On Thursday 31 May 2007 20:24, Bobby Moretti wrote:
This is an example of trying to err on the side of being overly correct
for
our output. For example, if you input
sage: sqrt(2)*5
it will get simplified to 5*sqrt(2). But this relies on the behavior of
maxima's simplification. \sqrt{2} \cdot 5 is much better than \sqrt{2}5,
which is what could happen if we left the cdot out in all cases.
I think the solution is to use some logic to remove the \cdot in some
cases, but leave it there in others. For example, juxtaposing two
numbers
with no dot to signify multiplication leads to confusing output, and in
fact the TeX function that comes with Maxima has this exact bug. One of
the
small projects I want to get done in the week between classes and SD4 is
redoing the symbolic output to be less redundant, and this fits in with
that.
On a similar note, there is another issue that would improve the output
significantly. I have expressions which are a product of about 5 things
and
they are output with excessive parentheses, for example:
(((1+a)(1+b))(1+c))(1+d)
The parenthesis check in the code just adds parentheses if the left
subexpression contains a minus or plus. Of course, it should check if
there
is a minus or plus that isn't already bracketed or something like that.
Would you like a trac bug for that?
That would be great. I've been working on rewriting that entire method with
much better thought out logic, so ideally it will get fixed.
In any case, the latex view functionality is IMO a huge feature of sage that
I've wanted in so many other systems. It's an absolutely essential
alternative to the screenful of symbols which are output from
Maple/Mathematica and others when stuff gets big (of course, maybe I'm
missing some features in the big M's).
I agree 100%. Although I think Mathematica, at least, draws something sort
of nice in its notebook. My guess is that Maple does the same. Still, we
have the opportunity to beat them here, with very little work on our part.
--
Joel
--
Bobby Moretti
[EMAIL PROTECTED]
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[sage-devel] Re: symbol number radian degree
On 5/21/07, Robert Bradshaw [EMAIL PROTECTED] wrote: On May 21, 2007, at 10:00 PM, Nick Alexander wrote: [EMAIL PROTECTED] [EMAIL PROTECTED] writes: On May 21, 7:24 pm, Yi Qiang [EMAIL PROTECTED] wrote: On May 21, 2007, at 7:18 PM, Brian Harris wrote: Fair enough. A previous discussion led me to believe the goal was for more transparent rings. Have you considered supporting something like the following? cos(3).toreal() Hmm.. there could be cos, cosdeg, sin, sindeg, etc, which are the expected symbolic functions. Then RR(cosdeg(180)) = -1, etc. Is that a bad idea? Global namespace pollution? Would the (implicit) target audience of degree-based trig know to look for sindeg, etc.? Would it work like sage: cosdeg(45) cos(pi/4) It's much better than a global state tough. It was never a question of global state. Sorry if I made it seem that way. If we were to do it (which still I disfavor), it might look something like sage: cos(45, units==degrees) 1/sqrt(2) ~Bobby -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: lisp.run is back?
There's definitely a problem with lisp.run staying around after SAGE has quit. I've been periodically noticing them a lot on my install of SAGE. That said, there could just be something wrong with my installation of SAGE. I'm going to be upgrading to 2.5 in a minute. I'll see if the problem persists. Since maxima is used *so much* in SAGE now, we'll know pretty quickly if it was a problem with my install or with the SAGE cleaner. As for the other processes, I have a screen session with 8 tty's multiplexed. All those other processes are in a sleep state and aren't using any processor cycles. ~Bobby On 5/8/07, mabshoff [EMAIL PROTECTED] wrote: On May 9, 5:40 am, [EMAIL PROTECTED] wrote: I'm seeing a lot of lisp.run processes on sage.math -- Bobby Moretti seems to own all them right now, but that's probably because he's been testing the calculus package / had a server up. Is the cleaner on vacation? ss.png 24KViewDownload He seems to be gone now :). What concerns me more is the lisp.run zombie: USER PID %CPU %MEMVSZ RSS TTY STAT START TIME COMMAND jacobml 26453 0.0 0.0 0 0 ?Zs May04 0:02 [lisp.run] defunct jacobml 26916 0.0 0.0 0 0 pts/29 Z+ May04 0:00 [poly.x] defunct If I recall correctly last time there were zombies the problem was caused by the external disc going bad/having a bad fs, so let's hope it is just a fluke. There are only two zombified tasks at the moment and that number hasn't increased in the last 12 hours or so. Knock on wood. Cheers, Michael -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: web page redesign
On 5/6/07, Timothy Clemans [EMAIL PROTECTED] wrote: The two column navigation table is very confusing to me. This might be a valid point. It's definitely not done very often. I think that web design has taken over content, which is pretty sad. Huh? The Sympy, Octave, and GMP sites are all good, because they provide all a lot of content in a clean web design. So while you guys don't use lists and css with them and use tables for layout, I'll be out constructing a larger site using meta tags, Google sitemap, and Google webmaster tools. So it will interesting to see what happens. Have fun forgetting about serious content and designing web pages that are not using modern code. You think that a succinct and tidy summary of what SAGE means to end users is not serious content? As far as the modern code goes, that would be nice, but I think a site that is visually appealing and doesn't inundate the user with too much information wins over modern code. On 5/6/07, William Stein [EMAIL PROTECTED] wrote: On 5/6/07, Mike Hansen [EMAIL PROTECTED] wrote: Looking good. There should be a bit more space above the Download SAGE for ... heading. Thanks. Fixed. Do we have a vector version of the logo or just a larger version that we can scale up so that it's not dominated by the text below? Yes, there is a vector version somewhere -- Alex Clemesha drew the logo using Inkscape (a nice free vector graphics program). Instead though, I tried shrinking the text below some which might be just as good. --Mike On 5/6/07, William Stein [EMAIL PROTECTED] wrote: Hello, I've significantly modified http://sage.math.washington.edu/home/was/rc/web/ based on many people's extensive (and greatly appreciated!) feedback.More feedback would be appreciated, though I think it's converging, and I have a lot of papers to grade :-). William -- William Stein Associate Professor of Mathematics University of Washington http://www.williamstein.org -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: sage calculus
Hey Joel, I'm wondering if we could have an update on the basic calculus rewrite which was discussed a while ago on the mailing list? I gave a very brief talk about this at SAGE Days 3. You can see my slides at http://sage.math.washington.edu/home/moretti/days3/talks/calculus.pdf if you haven't already. Currently, nearly everything that was discussed in our thread has been implemented. Of course, for every piece that has been implemented, it seems like we discover several other missing features that we didn't think originally discuss. Still, the basic functionality is there. I'm currently working on fixing a few issues (making plotting work correctly, making a seamless transition between symbolic and numerical computation, and fixing a lot of bugs). I'm going to be sending William a patch very soon (by tomorrow) to be included with the next version of SAGE. I can send you a patch as well, if you'd like some more time to play around with it/prepare your talk. I'm giving a talk on SAGE in a week and I might want to have a basic calculus demo if it's ready to show. I'm also wondering what are the most common usage methods of SAGE: 1) notebook 2) command line sage prompt 3) file.sage or file.py scripts Other methods??? My own personal favorite is #3 and I use the sage prompt to figure out what command to use in my scripts and do very quick checks. I don't really expect everyone to reply with their vote, but I'd appreciate if a few people did (especially people who see other people use sage). As far as this goes, I use a mix of all three. The notebook is nice for the reasons mentioned by others. The command line is nice for when I need to just test a couple simple lines. The attachment method I use occasionally, since for me, writing long pieces of code in the notebook is annoying (indentation is a pain). ~Bobby -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: sage.math dead as a doornail?
On 12/22/06, Bill Hart [EMAIL PROTECTED] wrote: Oh, I just happened to be running two connections to SAGE.math when it died. One was running the ssmul-profile program which you see there. The other was running the program top, which displays exactly the information you saw in my post. I just took a capture of the information after it froze on my screen (I work in windoze). I don't know if either dav or burhanud drove sage mad. Although both processes were using a lot of memory, they had been both running stably for a long time. According to the chart, SAGE still had 5g of free memory anyway. I only posted the info in case someone more guru than me could spot a particular process that might have led to the crash, and because I wonder if nobody is a real user. The program I was running was writing a file when sage crashed. I did run the program to standard output for some time to check it, before piping it to a file. So I think it was behaving, but one can never know. Bill. -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: 3D Java Visualization
On 12/12/06, David Joyner [EMAIL PROTECTED] wrote: Speaking from ignorance, I'm not enthusiastic about a java requirement but can be convinced otherwise. (1) Can we realy distribute it now (since it is not yet GPL'd)? We can't distribute java. However, we can distribute java applets, because we wrote the code, and thus own the copyright over it. They just won't be able to run without the (as of yet) non-GPL'ed virtual machine. (2) is it really fast? I have found that java is annoyingly slow. Java has really slow startup time, which is really noticeable when it halts Firefox. But you can expect applets to run prettty fast, once they're running. Java in browsers *seriously* annoys me as well. In fact, it sort of makes me cringe to think about Java applets in SAGE, as I *hate* sites that have Java applets. On the other hand, I don't know if there's much of an alternative. In fact, I usually block java (for security reasons, among others) on my browsers. (3) Is it really cross-platform? From Debian to FreeBSD to Mac OSX to windows? Relatively. As long as those systems have VMs written for them. They all have (non-open source) VMs/bytecode compilers written for them. I think we can expect everything about Java to improve dramatically as Sun releases these under the GPL William Stein wrote: On Mon, 11 Dec 2006 18:50:15 -0800, Robert Bradshaw [EMAIL PROTECTED] wrote: I've been looking into the java3d api stuff. ( https:// java3d.dev.java.net/ )It has about every feature you can imagine and is very fast (especially if you have OpenGL on your machine). There is only one problem--it is an optional package. In fact, most people who have java won't even have it installed. I think requiring users to install it is not only a hassle but also one benefit of the notebook is that we make no assumptions other than a relatively modern browser. Is this too much of an obstacle? I don't know. I'd like to get feedback from more people. Already requiring JAVA is an obstacle, but it's a reasonable one. What does sage-devel think? William -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: SEP
David: Thanks so much! I'm using it as a starting point. I took the liberty of adding a SEP section to the wiki, with this as the first SEP. I'm currently going through and trying to make it as specific as possible. As this is pretty significant undertaking, I think that it will end up being quite a bit longer than most of the PEPs that I saw, but I think that's okay. Anyway, the page is: http://sage.math.washington.edu:9001/CalculusSEP I'm editing it as I go, so most of it is pretty unreadable at this point, but anyone can see how far I've gotten by viewing it. ~Bobby On 12/7/06, David Joyner [EMAIL PROTECTED] wrote: Bobby: Here is a very rough draft - a starting point at least. - David SEP Authors - Bobby Moretti, David Joyner Preamble -- Functions for calculus Abstract -- A Python class structure is needed to provide SAGE with the ability to do calculus calculations. Easy of use of the syntax is a top priority. Copyright -- Public domain Specification -- This is a summary of emails from William Stein, Bobby Moretti, Joel Mohler, Alex Clemesha, Robert Bradshaw, David Joyner, David Harvey, Tom Boothby, The specifications shall be illustrated by a proposed example in pseudo-code: f = alg expr (Here by algebraic expression we mean anything built up from certain primitives using +,-,/,*,^, composition, and maybe more (e.g., integral, derivative, etc.). The structure for this is already implemented in the sage/functions directory. ) f.subs(var, val, ...) f.subs(dict) f.subs(list of pairs) implement recursively, with base case functions of 1 var and vars and constants being clear. f.subs(var=val, ...) f.function(*args) - returns a callable version of f, which otherwise works in same way. Output is result of subs. this just another formal function, but with a call method. Also, function((vars...),expr) makes an evaluatable function. f.derivative(var) - we completely implement. f.integral(var, optional endpoints) - feed expr to maxima (or maple or mathematica or mathomatic or yaccas or??) and let it compute integral symbolically. Sage_eval the result (if possible - if that fails, maybe wrap the external object formally). Basic functions would include all functions like sin, cos, exp, special funcs, etc, will be defined as formal functions - a lot of this is already done. We could possibly add the following type of function as well: f = (sin(x)*cos(x+y+3)).function(x,y) or dummy = sin(x*) * cos(x+y+3) f = dummy.function(x,y) Also, with my proposal one could also already type f = function( (x,y), sin(x)*cos(x+y+3) ) Here this would be implemented via: def function( vars, expr): return expr.function(*vars) Motivation -- For SAGE to have wide-spread acceptance in calculus, ease-of-use is critical. The current situation, illustrated with lambda functions, ElementaryFunctions, or built-in Python functions is inadequate. Rationale -- Though Maple and Mathematica have functionality with regard to calculus computations which SAGE is currently lacking, something better is needed. The syntax is still frustrating and unnatural for many new users, even for these sophisticated CAS's. Many find these systems very counterintuitive to do basic calculus. Part of the problem is the difference between mathematical functions and computer language functions. This SEP asserts that SAGE can do better and can provide a simpler system. Backwards compatibility - This will be a new class and will provide new functionality which will not interfere with previous implementations. References -- * wiki page http://sage.math.washington.edu:9001/BasicCalculus * emails in the Sage (Fwd) and SAGE calculus threads http://groups.google.com/group/sage-devel On 12/7/06, Bobby Moretti [EMAIL PROTECTED] wrote: On 12/7/06, William Stein [EMAIL PROTECTED] wrote: On Thu, 07 Dec 2006 04:30:28 -0800, David Joyner [EMAIL PROTECTED] wrote: On 12/7/06, Bobby Moretti [EMAIL PROTECTED] wrote: On 12/7/06, William Stein [EMAIL PROTECTED] wrote: Hi, Could somebody volunteer to write up a SAGE Enhancement Proposal for Calculus functions based on all the discussion on this list during the last 48 hours? Alex? Bobby? David? Joel? William I'd be glad to. I'd be happy to help you if you want any. I don't know what a SEP is supposed to look like though. There's never been a SEP before. It should be modeled on the Python PEP = Python enhancement proposal. Please look at a couple of these for some good examples: http://www.python.org/dev/peps/ One the PEP is written, probably Alex and I will implement the first version of it for SAGE. William Yes, I assumed you'd want it modeled after the PEPs. I'm going to make a wiki page for it once I have an outline of what the proposal will look like. Anyone, please feel free
[sage-devel] Re: SEP
On 12/7/06, William Stein [EMAIL PROTECTED] wrote: Hi, Could somebody volunteer to write up a SAGE Enhancement Proposal for Calculus functions based on all the discussion on this list during the last 48 hours? Alex? Bobby? David? Joel? William I'd be glad to. -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: SEP
On 12/7/06, William Stein [EMAIL PROTECTED] wrote: On Thu, 07 Dec 2006 04:30:28 -0800, David Joyner [EMAIL PROTECTED] wrote: On 12/7/06, Bobby Moretti [EMAIL PROTECTED] wrote: On 12/7/06, William Stein [EMAIL PROTECTED] wrote: Hi, Could somebody volunteer to write up a SAGE Enhancement Proposal for Calculus functions based on all the discussion on this list during the last 48 hours? Alex? Bobby? David? Joel? William I'd be glad to. I'd be happy to help you if you want any. I don't know what a SEP is supposed to look like though. There's never been a SEP before. It should be modeled on the Python PEP = Python enhancement proposal. Please look at a couple of these for some good examples: http://www.python.org/dev/peps/ One the PEP is written, probably Alex and I will implement the first version of it for SAGE. William Yes, I assumed you'd want it modeled after the PEPs. I'm going to make a wiki page for it once I have an outline of what the proposal will look like. Anyone, please feel free to help! -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Fwd: Re: [sage-devel] Re: Sage (fwd)
On 12/6/06, William Stein [EMAIL PROTECTED] wrote: --- Forwarded message --- From: Jaap Spies [EMAIL PROTECTED] To: David Joyner [EMAIL PROTECTED], William Stein [EMAIL PROTECTED] Cc: Subject: Re: [sage-devel] Re: Sage (fwd) Date: Wed, 06 Dec 2006 15:39:24 -0800 David Joyner wrote: just an amusing illustration of the frustrations we want to try to avoid. I really believe that because of the talented and inventive programmers working on SAGE, we can actually do better than both. I really hope so! I prefer Maple above Mathematica, but they are both a pain ... When I was messing around with Mathematica (couldn't get my hands on Maple, but I probably would have had a similar experience) back in high school, I found it *very* counterintuitive to do basic calculus. I essentially gave up trying. And given the amount of confusion about how Mathematica works displayed so far on this thread, my guess is that I am not alone. Part of the problem is the difference between mathematical functions and computer language functions. The idea of substituting parameters is present in mathematics... if I define f(x) = x sin (x^2) mathematically, and I want to evaluate it at some point in the domain, I just *do* the substitution. I don't typically write something separately. I'm afraid that this subtlety will likely be lost on most SAGE users. Extensive knowledge of computer programming is not required in order to use SAGE. I hope we can come up with a solution that is acceptable in both paradigms. Perhaps the solution that Math/Maple/etc. use is the best, but I hope we can find a more intuitive one. -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Sage (fwd)
On 12/5/06, William Stein [EMAIL PROTECTED] wrote:
On Tue, 05 Dec 2006 08:56:22 -0800, Joel B. Mohler
[EMAIL PROTECTED] wrote:
William, thanks for your kind hint for me to be quiet a bit. I believe
you are
right that I should be so. After this e-mail and a few additions to the
wiki, I
will be quiet on this topic.
No, don't be quiet!!
However, I don't agree that the suggestion of using variables from the
polynomial ring is doing what mathematica does. Some Examples:
Exhibit 1: My understanding is that you want f(1) to be 1 in sage, but
mathematica is not so.
In[1]:= f=x
Out[1]= x
In[2]:= f(1)
Out[2]= x
Exhibit 2: Mathematica has a dummy variable.
In[12]:= f[x_]:=Sin[x]
In[13]:= f'[x]
Out[13]= Cos[x]
In[14]:= f'[y]
Out[14]= Cos[y]
Exhibit 3: Part of the expected second variable is the name of the
independent
variable.
In[6]:= Plot[Sin[x]]
Plot::argmu: Plot called with 1 argument; 2 or more arguments are
expected.
I was also confused about this.
Maple and Mathematica have symbolic expressions, like Sin[x] * Cos[y],
(or sin(x)*cos(y)), which you *can not* evalaute in those systems!
You can only do a variant of substitution. This is what we should
do too, and doesn't require the preprocessor. In order to define
a function to be evaluated, one should just use Python's def or lambda.
Example in Maple:
auth2-213:~/s/spkg/standard was$ maple
|\^/| Maple 10 (APPLE PPC OSX)
._|\| |/|_. Copyright (c) Maplesoft, a division of Waterloo Maple Inc.
2005
\ MAPLE / All rights reserved. Maple is a trademark of
Waterloo Maple Inc.
| Type ? for help.
f = sin(x);
f = sin(x)
f(2);
f(2)
f;
f
f := sin(x);
f := sin(x)
f;
sin(x)
integrate(f, x);
-cos(x)
f(2);
sin(x)(2)
subs(x=2,f);
sin(2)
Example in Mathematica:
auth2-213:~/s/spkg/standard was$ math
Mathematica 5.2 for Mac OS X
Copyright 1988-2005 Wolfram Research, Inc.
-- Terminal graphics initialized --
In[1]:= f := Sin[x];
In[2]:= f[2];
In[3]:= f[2]
Out[3]= Sin[x][2]
In[4]:= Integrate[f, x];
In[5]:= Integrate[f,x]
Out[5]= -Cos[x]
OK, I forget how to subst in mathematica, but I have to go now.
Also, PARI has this same distinction too.
? f = x*y
%2 = y*x
? f(2,3)
*** unused characters: f(2,3)
^-
? subst(f,x,2)
%3
= 2*y
William, I know you're busy right now, but when you get a chance could
you give an example of what a SAGE session with this type of
substitution would look like?
--
Bobby Moretti
[EMAIL PROTECTED]
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-~--~~~~--~~--~--~---
[sage-devel] Re: Sage (fwd)
On 12/3/06, William Stein [EMAIL PROTECTED] wrote: On Sun, 03 Dec 2006 10:38:20 -0800, Joel B. Mohler [EMAIL PROTECTED] wrote: ... Perhaps the most important is Exhibit 2. To my eyes, a function definition is not complete with-out a clearly defined argument list. Piggybacking on top of argument lists to polynomial rings seems like it will lead to endless pains of the nature of the creatures above. This is simply how symbolic mathematics, in particular calculus, works. It does lead to pain and confusion in many calculus classes. I don't think dealing with this will be easy. But I think it's absolutely crucial in order for SAGE to ever be a viable alternative to Maple/Mathematica. Agreed. All your examples above are very good, and will help inform the design that we come up with. Thanks! Keep 'em coming! (Could somebody please post something based on all this into the wiki -- I suddenly only have limited net access for the next few days). Done. -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: Sage (fwd)
On 12/1/06, William Stein [EMAIL PROTECTED] wrote: On Thu, 30 Nov 2006 19:16:39 -0800, [EMAIL PROTECTED] wrote: Below is a message from a student who I met, who had tried to use SAGE but a) found the dependence on knowledge of rings to be awkward I think currently SAGE is not aimed at people who haven't had a course in abstract algebra. This is definitely the case. While one does not need to understand all the ins and outs of ring theory in order to make a matrix in SAGE, you at least have to understand the connection between rings and matrices. This is going to be, at the very least, intimidating to people who have never heard of a ring. And if they have to mess with algebraic structures at all, they may consider it an annoying and unnecessary waste of time. Various people have done a lot of work for SAGE that is aimed at such people, but frankly I do not have a good strategy to make SAGE accessible to people who know about groups, rings, fields, etc. I'm interested in starting some brainstorming about ways to make SAGE very accessible to people who don't know about those algebraic structures. Yes, let's come up with such a strategy. I do think we need a unified plan. If not, we run the risk of having a bunch of different implementations of software aimed at such people, each having low interoperability both amongst themselves and with the other areas of SAGE. Ideas? For starters, perhaps David Kaplan could suggest a couple of specific sample problems that he would like to use SAGE to solve, and we could think about how: (1) they could be done, but require unreasonable knowledge of algebra (2) they can't be easily done right now, but could be if we put some additional code in SAGE. SAGE includes Maxima, and Maxima is extremely capable at Calculus related computations -- so one question is how to make such capabilities available from SAGE without the user having to know anything about maxima (or even what maxima is). So far SAGE is terrible at this, compared to how good it could be. Looking at the actual problems that people might want to do is a good way to get started. But again, I'd caution against taking too much of an ad-hoc approach. I think that calculus is a great place to start. First of all, we do have Maxima. Also, having an easy-to-use calculus package that displays its output prettily is a must for any self-respecting CAS. With jsMath and Maxima, we have a real potential to blow away the competition here. And finally, calculus is kind of a lowest common denominator among people who are using a CAS. It's probably the first thing that any non-mathematician would try... first impressions are important. Re. brainstorming, I'd like to do this. Maybe after the meeting today, or sometime on Monday? I know things are busy getting 1.5 ready for release, so maybe we should wait until after that gets out the door. b) didn't get much info out of the documentation. He's very excited about open source software, especially for mathematics, and seems to be interested in working on documentation. One thing he explicitly expressed interest in was helping make a short tutorial for getting started with SAGE. David J., you're working on such a thing, aren't you? -- Forwarded message -- Date: Thu, 30 Nov 2006 17:06:28 -0800 (PST) From: David Kaplan [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Sage This is my email. I am interested in helping the Sage Project in any way possible. I was thinking documentation. Dave K. Im working on Mandriva Linux, btw, but I can test on the standardized cygwin binary too. -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: DIE LISP.RUN ZOMBIES DIE
It looks like every currently running lisp.run process has been reniced to 19. It sounds like this problem should go away after Thanksgiving and SAGE 1.5... -- Bobby Moretti [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
[sage-devel] Re: syrex
pyrecs? pyreks?psyrex?(where the s is for SAGE).Of course this would mean that we would call pyrexc pyrecsc or pyreksc which is sort of incomprehensible. This also has the disadvantage of being a homonym with pyrex. I'm trying to think of a glassware-related pun that would be appropriate... On 11/3/06, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:pyragesagerexsageXSAGeXtremelyFastExtensionLanguageScript hypersageOn Fri, 3 Nov 2006, David Harvey wrote: On Nov 3, 2006, at 2:51 PM, William Stein wrote: On Fri, 03 Nov 2006 11:42:29 -0800, alex clemesha [EMAIL PROTECTED] wrote: I vote for Spyrex too, not syrex ... that sounds like some medical device :) Robert Bradshaw pointed out that Spyrex sounds like *spyware*! Also, when I say syrex, I might spit on somebody.Maybe an entirely different name would be a good idea, though.The purpose of the program is to make it easier to write fast extension code for SAGE. Any ideas for a name that captures that? I prefer that the name indicates that it's derived from Pyrex. Otherwise no fair to the author. Maybe just sage-pyrex. S-Pyrex. Pyrex-S. Expyre. I dunno. David [EMAIL PROTECTED] --~--~-~--~~~---~--~~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~--~~~~--~~--~--~---
