[sage-support] Re: Symbolic convolution usage Sage
On Dec 22, 5:08 pm, Maxim maxim.courno...@gmail.com wrote:
Hi all!
I'm trying to do something which I haven't seen any examples so far :
symbolic convolution. I know I can use lists or Piecewise defined
functions to do a convolution, but here my interest is the symbolic
solution.
To illustrate an example, I would like to make a function that would
do something like that :
def conv(func1,func2):
# variable change
var('t')
h(tau)=func1(tau)
x(tau)=func2(-tau+t)
# proper convolution returns y(t)
y(t) = integrate(h(tau)*x(tau),tau,-infinity,+infinity)
return y(t)
SNIP
I do not know sage well enough, but can't one in Sage just pass the
independent variable, say t, as an additional argument to the conv()
function and inside the conv() function, simply write the definition
of the convolution integral?
This is the convolution of your 2 given functions
unit_step(t), exp(-0.5*t)*unit_step(t)
So, in Mathematica, I write the following 4 lines of code:
f1[t_] := UnitStep[t]
f2[t_] := Exp[-0.5*t]*UnitStep[t]
conv[f1_, f_, t_] := Integrate[ f1[tao]* f2[t - tao], {tao, -
Infinity, Infinity} ]
(*now do the convolution*)
conv[f1, f2, t]
Out[11]= (2. - 2./E^(0.5*t))*UnitStep[t]
The above is y(t).
Can't the above be translated to Sage?
--Nasser
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[sage-support] how to scroll down more when doing ?? for long listing?
hi; I have 2 questions below: I created an account on sagenb.org, and when I do solve?? I get the listing, but it does not list the whole code, and there is no way for me to look below what is shown on the screen (there is no scroll bar for use to scroll down more). My browser ofcourse has scroll down bar, but not for the listing itself. Is this a feature of the server or a bug? I also find it strange that I could not use wild card for searching, I keep forgetting name of commands. It would nice if one in sage can write *solve*? No object '' currently defined. to get listing of all functions in which the word 'solv' is in its name, as I can do in Mathematica: *solve*? System` DSolve LinearSolveFunction NSolve SolveAlways FrobeniusSolve MainSolve RSolve SolveDelayed LinearSolve NDSolve Solve AbstractAlgebra`Master` RingSolve May be this can be added for a future release as it is really useful to have. --Nasser -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: how to scroll down more when doing ?? for long listing?
On the scroll part: I think it is my error. My eyes are trained to look for closing end if and some sort of end of function indicator. So I assumed there is more code to follow since I saw an 'if' and no closing for the 'if' After I posted this, I realized that the listing is all there is, and this is, like, pyhton, duh, and it has no end if, and end def, but uses indentation to indicate the structure of the code. silly me. I find it nice that one can list the source code. --Nasser I also find it strange that I could not use wild card for searching, I keep forgetting name of commands. It would nice if one in sage can write *solve*? No object '' currently defined. to get listing of all functions in which the word 'solv' is in its name, as I can do in Mathematica: *solve*? System` DSolve LinearSolveFunction NSolve SolveAlways FrobeniusSolve MainSolve RSolve SolveDelayed LinearSolve NDSolve Solve AbstractAlgebra`Master` RingSolve May be this can be added for a future release as it is really useful to have. --Nasser -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] http://www.sagenb.org/ keeps crashing when using search box
fyi; when I go here http://www.sagenb.org/ login as guest, then I type something in the search box, the server will crash or give me an internal error. --Nasser -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Something like Mathematica's `Interact`?
On Nov 21, 3:53 pm, William Stein wst...@gmail.com wrote: I have the impression that Maplets are somewhat different than Mathematica's Manipulate and Sage's @interact. I'm not so familiar with them -- I read about them online just now, and it seems like they are basically a Maple interface to a subset of the Java Swing GUI API. I *just* tried to use one from the official Maple website, and it promptly completely crashed Firefox (latest version, on OS X). Luckily gmail saved my message so I didn't loose this email! There is also Google's Mapplets, not to be confused with Maple Maplets http://code.google.com/apis/maps/documentation/mapplets/ http://www.adeptscience.co.uk/products/mathsim/maple/primes/maplets.html Wonder if MapleSoft can bring a lawsuit against google for name infringement here? This is one way Maplesoft can make few easy millions of dollars? :) Notice when searching for maple maplets, google suggests a name correction to mapplets. Very smart. I do not dare touch a Maple maplet any more, since every time I tried, all sort of Java errors popup in my browser, many times freezing it or worst. I never did like Maplets myself. I need to try sage interact more sometime. But I do like Mathematica Manipulate. It is complicated and it takes time to learn. William --Nasser -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Something like Mathematica's `Interact`?
On Nov 21, 3:53 pm, William Stein wst...@gmail.com wrote: I have the impression that Maplets are somewhat different than Mathematica's Manipulate and Sage's @interact. I'm not so familiar with them -- I read about them online just now, and it seems like they are basically a Maple interface to a subset of the Java Swing GUI API. I *just* tried to use one from the official Maple website, and it promptly completely crashed Firefox (latest version, on OS X). Luckily gmail saved my message so I didn't loose this email! There is also Google's Mapplets, not to be confused with Maple Maplets http://code.google.com/apis/maps/documentation/mapplets/ http://www.adeptscience.co.uk/products/mathsim/maple/primes/maplets.html Wonder if MapleSoft can bring a lawsuit against google for name infringement here? This is one way Maplesoft can make few easy millions of dollars? :) Notice when searching for maple maplets, google suggests a name correction to mapplets. Very smart. I do not dare touch a Maple maplet any more, since every time I tried, all sort of Java errors popup in my browser, many times freezing it or worst. I never did like Maplets myself. I need to try sage interact more sometime. But I do like Mathematica Manipulate. It is complicated and it takes time to learn. William --Nasser -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Re: Benchmarks w.r.t Matlab
On Oct 22, 11:59 am, William Stein wst...@gmail.com wrote:
Here's a benchmark (the first thing I tried):
sage: a = random_matrix(RDF,2000)
sage: timeit('a*a')
5 loops, best of 3: 1.8 s per loop
sage: b = matlab('rand(2000)')
sage: timeit('b*b')
5 loops, best of 3: 3.4 s per loop
Sage is twice as fast.
Hi,
how do you run matlab command from sage like this above? I have sage
4.1.2 and matlab 2008b installed on my windows XP PC, but when I run
the above, it tells me it can't start matlab:
a = random_matrix(RDF,2000)
timeit('a*a')
5 loops, best of 3: 2.17 s per loop
b = matlab('rand(2000)')
timeit('b*b')
TypeError: Unable to start matlab
I assume I need to do some 'configuration' documented somewhere which
I did not even try to look for. may be because iam student and using
student version of matlab?
But when I run the above inside my matlab itself, then this is what I
get:
If I understand what timeit() does above, I just had a quick look at
its documentaion, is that it ran b*b 5 times, took the mean, then
repeated this 3 times, then at the end it took the lowest (best) of
all the means found?
if so, then I get 1.03 seconds with matlab, which is twice as fast as
sage? if my above understanding of timeit() is wrong, I could redo
this: (there is no timeit() in matlab, so had to write few lines of
code to emulate it)
b=rand(2000);
timesall=zeros(3,1);
times=zeros(5,1);
for i=1:3
for j=1:5
tic; b*b; times(j)=toc;
end
timesall=mean(times);
end
min(timesall)
timesall =
1.0300
Using Mathematica 7.0, I did the same, and I get 1.14 seconds
In[1]:= b = Table[RandomReal[UniformDistribution[{0, 1}]], {2000},
{2000}];
timesall = Table[0, {3}];
times = Table[0, {5}];
For[i = 1, i = 3, i++,
{
For[j = 1, j = 5, j++,
times[[j]] = Timing[b . b][[1]]
];
timesall[[i]] = Mean[times];
}
]
Min[timesall]
Out[6]= 1.14380001
ps. I am using the notebook interface with sage with sun virtual box.
may be this adds more delay? should I run the sage command from the
sage command line?
all on same PC, no other apps runnings at the same time. Intel 2 core
Due E6850@ 3 Ghz , 3 GB ram, windows XP sp2
--Nasser
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[sage-support] Re: maximum
On Oct 20, 8:44 am, finotti luis.fino...@gmail.com wrote: Sorry... My fault. I had a max=20, which made max? give me: This is really bad that one can redefine a system function just like this. This is also a problem in other systems such as Matlab, which causes confusion specially for new users who do not know that there is a system function or a constant called say pi or int or sum or max or etc.., and then they overwrite by making a variable of the same name. I was hoping that Sage would have been designed to prevent such silly things errors by having system functions and symbols be protected from being redefined. But this might not be possible due to the nature of the system and language used. In Mathematica, one thing I like about it, is that all its functions and symbols are protected by default (and they all start with Uppercase), so one can not do such a trivial mistake. --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: maximum
Suppose I write a program in Mathematica 7.0 that happens to use a variable Foo. Then Mathematica 8.0 comes out and Foo is a function name that Mathematica decided to use. Does that mean my program is now broken? William Hi; In theory, Yes. But one could, if they want to, Unprotect Mathematica's Foo[] function first, and then they can define their own function to be called Foo[]. That is why it is common knowledge in the Mathematica community that no one would define a function name or symbol or variable that starts with UpperCase. http://reference.wolfram.com/mathematica/tutorial/DefiningVariables.html There is a convention that built-in Mathematica objects always have names starting with uppercase (capital) letters. To avoid confusion, you should always choose names for your own variables that start with lowercase letters. Small price to pay for consistency and avoiding problems such this one here. Would you not agree? --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: shift-return, shift-enter, click-mouse-on-evaluate. on evaluating a cell in a notebook
On Apr 21, 3:13 am, Minh Nguyen nguyenmi...@gmail.com wrote: My laptop has only ENTER. To do what you're suggesting, I have to hold down the key FN and press ENTER. Since you said you are using Mathematica, and on your laptop there is no ENTER key, only the RETURN key, and so you had to suffer and hit SHIFT-RETURN each time to evaluate a cell (like with SAGE now), then you could edit the Mathematica key binding file on your installation, and configure another key to send SHIFT-RETURN, so you would only need to press one key after that. I just found about this file myself. For example on how to use, Please see http://www.lamberta.org/blog/mathematica-keybindings/ or google the file name. The file name is called keyEventTranslations.tr and I think this is as of version 6 of Mathematica. I think this solution is something that SAGE could adopt. i.e. Have a keyEventTranslations.tr type file with SAGE installation, and have it set to work as default as things act now. Then one could edit this file to reconfigure key binding. This way one would not need to resort to outside scripts or buy programmable keyboards and such. --Nasser ps. When I use my laptop, which also has no ENTER key, I never use the laptop own keyboard, I always attach my standard USB keyboard to the laptop and use that. It is much easier to use the large keyboard than those tiny keyboards that come build-in with laptops and the USB keyboard has the ENTER key as well, so I never noticed this problem you mentioned. --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] sage interact. Can one run it on the web?
Simple question I hope. I see a number of interesting sage interaction code here: http://wiki.sagemath.org/interact Right now, to run any, I copy the code to my open notebook in the browser (I am on windows, so I am using VMWare and access sage via browser), then I evaluate the code copied to be able to actually interact with the code. Is there a way for someone to do such an interaction and post it on the web for others to use directly from the web, without having to have sage installed and without having to do what I am doing now? (i.e. copy code etc...) If so, this would be really cool. If not, any plans to have this feature in the future in sage? It would be like running a applet inside the browser in a way. Thanks, --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] shift-return, shift-enter, click-mouse-on-evaluate. on evaluating a cell in a notebook
Hello; It is a bit annoying having to hit 2 keys (i.e. reach out and use both hands) each time in order to evaluate a cell in sage notebook. I am using windows, and I have to hit SHIFT-ENTER, or SHIFT-RETURN, or I could use the mouse, point it to the little 'evaluate' link below the cell, which is also annoying. But it would be much easier to have ONE key. In Maple, the RETURN key will cause evaluation, and in Mathematica the ENTER key. Can one tell sage to use the ENTER key only (without the shift) to cause cell to evaluate? and have the RETURN key just starts a new line (i.e. as in Mathematica). May be with some options or some configuration setting somewhere? I think Mathematica got it right here. In Maple, to start a new line and not cause evaluation, one hits SHIFT-RETURN (again, this is using the notebook interface, i.e. via the browser interface). Thanks, --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: shift-return, shift-enter, click-mouse-on-evaluate. on evaluating a cell in a notebook
On Apr 21, 1:40 am, Minh Nguyen nguyenmi...@gmail.com wrote: But it would be much easier to have ONE key. In Maple, the RETURN key will cause evaluation, and in Mathematica the ENTER key. That statement about Mathematica is very strange to me. With an install of Mathematica 6 out of the box and not fiddling with anything, I have to use Shift-ENTER or Shift-RETURN to evaluate in the worksheet. But I assume that you've done some fiddling with your Mathematica settings to get it just evaluate upon hitting ENTER or RETURN? Are you on a mac? I've done no fiddling. On windows, if one hits the ENTER key in Mathematica, the cell is evaluated. The ENTER key is that key in the numeric keypad group, usually to the right side of the keyboard. The RETURN key is that (usually) big key in the main keyboard group. RETURN is usually called CR (Carriage return) ascii code 13 ENTER is line feed , ascii code 10 After I wrote the above, I searched wikipedia, and there is a article with pic which explains the difference. It seems from this article, that this difference is not on all keyboards. I use standard PC keyboard, and this is always how it worked. see http://en.wikipedia.org/wiki/Enter_key --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: shift-return, shift-enter, click-mouse-on-evaluate. on evaluating a cell in a notebook
On Apr 21, 4:57 am, kcrisman kcris...@gmail.com wrote: Hi Nasser, Just out of curiosity, what about Shift-Return (as opposed to Shift- Enter)? If I use my thumb, I can even press both with the same finger, though usually I use 2nd and 3rd fingers. Or does that not work with your keyboard configuration? Hope we can help you resolve this soon! - kcrisman Yes. SHIFT-RETURN could be done with one hand because as you said, the RETURN key is in a very close proximity to the SHIFT key (on my keyboard at least). The problem though, to do this with one hand, one must twist the thumb in 90 degree angle as one it hitting on RETURN key with the index finger, (I do not think I could press both keys with just one finger), and my thumb has a bit of arthritis which makes hard to bend it too much. It is also a bit awkward to hit a key with a finger twisted in this fashion. I just tried it. But it is a good suggestion and shows imagination and thinking outside the box. I think another solution would be to get one of those programmable keyboards and program it to send SHIFT-RETURN when hitting some F key which is not used. And use that F key for SAGE only. Meanwhile, I have to continue to reach out and use both hands in order to evaluate a SAGE cell. --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Problem Sage 3.4 windows XP
On Mar 18, 1:33 pm, William Stein wst...@gmail.com wrote: On Wed, Mar 18, 2009 at 1:22 PM, madison.mich...@gmail.com wrote: I am also having a problem running Sage 3.4 on windows XP. Vmware starts up, but when I run the notebook command it flashes the IP Just out of curiosity, has *anybody* successfully used sage-vmware-3.4.zip? Maybe it is seriously broken? William I downloaded sage-vmware-3.4.zip on my XP SP2, and doubled click on the vmx and it starts up with no problem, and the I am using it now from firefox. 4 GB RAM, the VM player I am using is 2.5, build=118166 --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] very basic sage question on objects and methods
I create a list, using v=[1..10] Now, I wanted to find the length of 'v'. I did help(list) and do not see a method to find the length of a list object. Then looking more around, I found I can type len(v) to find the length of 'v'. But this is not OO? Why is there no method to find the length of a list (I mean as a method in the class itself). I was expecting to type object.len() or something like this. I am using 3.4 version Thanks. --Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Mathematica 7 coming
On Nov 14, 3:41 pm, William Stein [EMAIL PROTECTED] wrote: * New computable data, including genomic data, protein data, and current and historical weather data Cool. I wonder what the license issues are with making such data available? Can somebody look into this? It is possible they are using federally supported websites, which are free to the public. There are many sources for such biological databases out there at government and academic sites, which requires no license to download the data and use. (I am talking about US based sites here). There are also microarray data, which is public domain. Matlab bioinformatics toolbox for example, has functions that one can call to download such data from these databases on the net. The format of database scheme is all public domain, so anyone can develop code to do the same. I assume Mathematica 7 is doing the same type of thing. Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] silly question? how to read sage source code? (on windoz)
I've just wanted to look at the source code on my PC. (I know I can browse it on net). I am using cygwin on windoz. I know building sage on cygwin is not supported. I just wanted to look at the source code. So, I've download the source code tar file and extracted. $ ls sage-3.1.4 sage-3.1.4.tar However, all the source is in spkg packages. I do not want to build it, just wanted to extract the source code from these packages. The makefile does not seem to have a target to allow one to extract the source code. I really do not want to go removing source code from each spkg file. Is there an easy way to do this? why not have a target in makefile to just extract the source code? thanks, Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: silly question? how to read sage source code? (on windoz)
Thanks for the replies. I did not know spkg was tar file also. This is a small bash script which extracts the source code. It looks like everything is in the /standard folder $ cat extract_source.sh #!/bin/bash cd sage-3.1.4/spkg/standard for i in $( ls *.spkg ); do echo extracting file $i tar -xjf $i done This below is listing of the above. I only show it because I saw couple of errors from some of the packages in case someone wants to looks into it. - extract sage source on windows under cygwin $ ./extract_source.sh extracting file atlas-3.8.1.p3.spkg extracting file blas-20070724.spkg extracting file cddlib-094b.p3.spkg extracting file clisp-2.46.p7.spkg extracting file conway_polynomials-0.2.spkg extracting file cvxopt-0.9.p7.spkg extracting file cython-0.9.8.1.1.p0.spkg extracting file doc-3.1.4.spkg extracting file docutils-0.5.spkg extracting file eclib-20080310.p7.spkg extracting file ecm-6.1.3.p0.spkg extracting file elliptic_curves-0.1.spkg extracting file examples-3.1.4.spkg extracting file extcode-3.1.4.spkg extracting file f2c-20070816.p0.spkg extracting file flint-1.0.13.p0.spkg extracting file flintqs-20070817.p3.spkg extracting file fortran-20071120.p5.spkg bzip2: (stdin) is not a bzip2 file. tar: Child returned status 2 tar: Error exit delayed from previous errors extracting file freetype-2.3.5.p0.spkg extracting file gap-4.4.10.p10.spkg extracting file gd-2.0.35.p1.spkg extracting file gdmodule-0.56.p4.spkg extracting file genus2reduction-0.3.p3.spkg extracting file gfan-0.3.p4.spkg extracting file ghmm-20080813.spkg extracting file givaro-3.2.13rc2.spkg extracting file gmp-4.2.2.p1.fake.spkg extracting file gnutls-2.2.1.p1.spkg extracting file graphs-20070722.spkg extracting file gsl-1.10.p1.spkg extracting file iml-1.0.1.p11.spkg extracting file ipython-0.8.4.p0.spkg extracting file ipython1-20070130.spkg extracting file jinja-1.2.spkg extracting file jmol-11.6.rc8.spkg extracting file lapack-20071123.p0.spkg extracting file lcalc-20080205.p2.spkg extracting file libfplll-2.1.6-20071129.p5.spkg extracting file libgcrypt-1.4.0.p2.spkg extracting file libgpg_error-1.6.p0.spkg extracting file libm4ri-20080909.spkg extracting file libpng-1.2.22.p8.spkg extracting file linbox-1.1.6.spkg extracting file matplotlib-0.98.3.p2.spkg extracting file maxima-5.16.3.spkg extracting file mercurial-1.01.p1.spkg extracting file moin-1.5.7.p2.spkg extracting file mpfi-1.3.4-cvs20071125.p7.spkg extracting file mpfr-2.3.2.spkg extracting file networkx-0.36.p1.spkg extracting file ntl-5.4.2.p4.spkg extracting file numpy-1.2.0.p0.spkg extracting file opencdk-0.6.6.spkg extracting file palp-1.1.p1.spkg extracting file pari-2.3.3.p0.spkg extracting file pexpect-2.0.p1.spkg extracting file polybori-0.5rc.p5.spkg tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux: Cannot mkdir: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/ stepbystep.install: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/ get_sat_table.sh: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/ beautify_units.sh: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/check_mem.sh: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/timeout.sh: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/Skeleton.h: Cannot open: Not a directory tar: polybori-0.5rc.p5/src/polybori-0.5rc/polybori/aux/release.sh: Cannot open: Not a directory tar: Error exit delayed from previous errors extracting file polytopes_db-20080430.spkg extracting file pycrypto-2.0.1.p2.spkg extracting file pygments-0.11.1.spkg extracting file pynac-0.1.p0.spkg extracting file pyprocessing-0.52.spkg extracting file python-2.5.2.p8.spkg extracting file python_gnutls-1.1.4.p3.spkg extracting file quaddouble-2.2.p9.spkg extracting file r-2.6.1.p21.spkg extracting file readline-5.2.p4.spkg extracting file rubiks-20070912.p8.spkg extracting file sage-3.1.4.spkg extracting file sage_scripts-3.1.4.spkg extracting file scipy-20071020-0.6.p4.spkg extracting file scipy_sandbox-20071020.p3.spkg extracting file scons-0.97.0d20071212.spkg extracting file setuptools-0.6c8.p1.spkg extracting file singular-3-0-4-4-20080711.p1.spkg extracting file sphinx-0.5.0svn66624.p0.spkg extracting file sqlalchemy-0.4.6.p0.spkg extracting file sqlite-3.5.3.p3.spkg extracting file symmetrica-2.0.p2.spkg extracting file sympow-1.018.1.p5.spkg extracting file sympy-0.6.2.spkg extracting file tachyon-0.98beta.p6.spkg extracting file termcap-1.3.1.p0.spkg extracting file twisted-8.1.0.p1.spkg extracting file weave-0.4.9.spkg extracting file zlib-1.2.3.p4.spkg extracting file zn_poly-0.9.p0.spkg extracting file zodb3-3.7.0.p1.spkg $ Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email
[sage-support] Re: question on using integral() in sage. Fourier transform of unit step function.
On Sep 21, 10:34 pm, Nasser Abbasi [EMAIL PROTECTED] wrote: Let me rewrite what I wrote in last post again, since it did not format well. I think it is still not clear, so I wrote it in latex via SW, here it is again as screen image and PDF file http://12000.org/tmp/092108/eq.gif http://12000.org/tmp/092108/eq.pdf I hope this is more clear. Nasser --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@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-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] question on using integral() in sage. Fourier transform of unit step function.
Hello;
I am a sage newbie. I'd like to find out how to make Sage give me
this same result that I get in Mathematica.
This is what I typed (I do not know how to cut/paste from the VMWare
player console to her yet, so if there is a typo it is because of
this).
f=var('f')
assume(f0)
integral( e^(-I * 2 * pi * f * t), t , 0 , Infinity)
The answer I get starts with
limit(sin(2*pi*f*t),t, etc...etc...
Is there a way to tell Sage to give me this answer I get from
Mathematica?
Assuming[Im[f] 0, Integrate[Exp[(-I)*2*Pi*f*t], {t, 0, Infinity}]]
-(I/(2*f*Pi))
Thanks,
Nasser
--~--~-~--~~~---~--~~
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[sage-support] Re: question on using integral() in sage. Fourier transform of unit step function.
On Sat, Sep 20, 2008 at 11:58 PM,NasserAbbasi[EMAIL PROTECTED] wrote:
Hello;
I am a sage newbie. I'd like to find out how to make Sage give me
this same result that I get in Mathematica.
This is what I typed (I do not know how to cut/paste from the VMWare
player console to her yet, so if there is a typo it is because of
this).
f=var('f')
assume(f0)
integral( e^(-I * 2 * pi * f * t), t , 0 , Infinity)
The answer I get starts with
limit(sin(2*pi*f*t),t, etc...etc...
Is there a way to tell Sage to give me this answer I get from
Mathematica?
Assuming[Im[f] 0, Integrate[Exp[(-I)*2*Pi*f*t], {t, 0, Infinity}]]
-(I/(2*f*Pi))
Thanks,
Nasser
On Sep 21, 2:49 pm, David Joyner [EMAIL PROTECTED] wrote:
This integral doesn't converge. Why do you think Sage should return
what Mma does?
I think it does converge.
int( exp(-I 2 Pi f t),{t,0,infinity) =
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi f t) }
0
Let f be complex in general, say (a+ I b) then the above becomes
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi (a +I b) t) }
0
or
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi a t) exp (2 Pi b t) }
0
Since b0, then the above becomes
1/(-I 2 Pi f) * [ 0 - 1 }
or
1/(I 2 Pi f)
or
-I/(2 Pi f)
which is what Mathematica gave.
Did I make a mistake in the above somewhere? Could you explain why
you think the integral does not converge?
Nasser
--~--~-~--~~~---~--~~
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[sage-support] Re: question on using integral() in sage. Fourier transform of unit step function.
Let me rewrite what I wrote in last post again, since it did not
format well.
I think it does converge.
int( exp(-I 2 Pi f t),{t,0,infinity) =
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi f t) }
0
Let f be complex in general, say (a+ I b) then the above becomes
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi (a +I b) t) }
0
or
infinity
1/(-I 2 Pi f) * [ exp(-I 2 Pi a t) exp (2 Pi b t) }
0
Since b0 (this is the assumption that Im(f)0 ), then the above
becomes
1/(-I 2 Pi f) * [ 0 - 1 }
or
1/(I 2 Pi f)
or
-I/(2 Pi f)
Nasser
--~--~-~--~~~---~--~~
To post to this group, send email to sage-support@googlegroups.com
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