gmane.comp.mathematics.maxima.general

Re: Please vote to add Maxima language to the list ofapproved programming languages in Sourceforge projects

Stefano Ferri — 2010-03-12T11:49:25


I've used wrong words, sorry...  When you publish a project, you can
select the language it's written in, and Maxima is not listed in the
menu. Mathematica, Matlab and other scripring languages are listed, so
I think it could be nice to have this possibility. Of course, it is
already perfectcly possible to publish programs written in Maxima
language!




Of course, it require some work, but I hope Soucerfoge guys will work on this.

Stefano

Re: Please vote to add Maxima language to the listofapproved programming languages in Sourceforge projects

Stanislav Maslovski — 2010-03-12T11:22:12

What does it mean in reality, the "list of approved languages"? I guess,
at the moment it is perfectly possible to host a project written in
Maxima on sourceforge, right? You host one?


This will require more work than just adding a language to the list and
has little benefits, IMO. Actually, sourceforge is going in the wrong
direction adding more and more bells and whistles to the pages...

--
Stanislav

Please vote to add Maxima language to the list of approvedprogramming languages in Sourceforge projects

Stefano Ferri — 2010-03-12T10:21:19

Dear list,

because I'm developing a program running in Maxima (SymSAP) and it is
hosted on Sourceforge, and Maxima is not listed between the available
programming languages, while Mathematica and Matlab there are, I've
requested the Sourceforge team to add Maxima syntax to the list of
official programming languages.
I've also suggested to add the highlighting rules to better read .mac
files when browsing CVS/SVN, and I've proposed as a solution to start
from the xml rules written for Kate by Alexey Beshenov.

If you think this could be a nice idea, please visit the Idea Torrent
page on Sourceforge and give a vote to my proposal to see it
implemented. There are a lot of approved ideas, and the Sourceforge
team will only work on the most popular/interesting, so voting is
important. You can fin my proposal here:


http://sourceforge.net/apps/ideatorrent/sourceforge/ideatorrent/?keywords=maxima


If the above link doesn't work, you can go here:

https://sourceforge.net/apps/ideatorrent/sourceforge/

and click on "Popular Ideas", then search for maxima (on the right
side of the page).

Please help :-)

Thanks!
Stefano

Re: Bug report ID:2960403 "spurious floats in asksign"

Dieter Kaiser — 2010-03-11T21:47:53

Am Dienstag, den 09.03.2010, 22:22 +0100 schrieb Dieter Kaiser:


I have a lot of problems with the bug. The only thing which seems to be
working is the revision 1.17. If I put in later changes step by step it
sometimes works sometimes not. The behavior is different if I only load
a change or compile and build Maxima. Furthermore, I do not find the
reason why we get a different behavior.

Some more work is needed.

Dieter Kaiser

Re: How to suppress ordering of arguments in arithmeticexpression

Robert Dodier — 2010-03-11T15:59:03


Try powerdisp:true which reverses the displayed order of
arguments in "+" expressions. Maybe that is enough.

best

Robert Dodier

How to suppress ordering of arguments in arithmeticexpression

primus — 2010-03-11T13:14:29

_______________________________________________
Maxima mailing list
Maxima< at >math.utexas.edu
http://www.math.utexas.edu/mailman/listinfo/maxima

Re: calculate complex integral of a sum

Janek Kozicki — 2010-03-11T10:09:16

Andrej Vodopivec said:     (by the date of Thu, 11 Mar 2010 09:15:32 +0100)



wow, indeed, reversing sum & integral works! Just the same as I did
when doing with pen&paper myself ;)

sum(integrate(1/(n^4+x^2),x,0,inf), n, 1, inf),simpsum;

thanks a lot! :)

Re: Some issues (a bug?) with triangularize

Stefano Ferri — 2010-03-11T09:33:57

I forgot to mention that I'm running Maxima 5.20.1. This problem is
present both on Windows version, compiled with GCL, and Linux version,
compiled with CLISP.



2010/3/10 Stefano Ferri <ferriste< at >gmail.com>:

Re: Maxima Notes

2010-03-11T08:27:48

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| From...: Edwin Woollett        woollett< at >charter.net
| To.....:                   pricek< at >surfaceoptics.com
| Cc.....: maxima mailing list maxima< at >math.utexas.edu
| Sent...: Wednesday, March 10, 2010 8:56 PM
| Subject: Re: [Maxima] Maxima Notes
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| ...
|
|    And if one of your computer motherboards die, you don't 
|    have to again pay out for a new license.
| 
| 2. My experience with Mathematica ended with version 4.something, 
|    which I have on a separate desktop (remember, I can't move it 
|    without paying the piper!). 
|
| ...
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

  All right, except for this case. Since you can ask then for 
  a new password with the same license and the new Machine ID. 
  
  Petros Zimourtopoulos
  http://www.antennas.gr

Re: calculate complex integral of a sum

Andrej Vodopivec — 2010-03-11T08:15:32

nusum in general does not work well for infinite sums. simpsum knows
how to do it.

(%i1) sum(1/n^2,n,1,inf)$
(%i2) %, simpsum;
(%o2) %pi^2/6

Andrej

Re: maxima with imaxima and xemacs, latex error.

Robert Dodier — 2010-03-11T01:40:41


Please post the offending LaTeX file;
I think you can find it by following the "Latex error in:"
(I think the error report tells where the file is).

What happens if you try to latex the file by hand?
i.e. try latex <whatever> at a shell prompt where
<whatever> is the name of the offending file.

Do I understand correctly that most expressions are
formatted correctly by Imaxima, and only
polarform(%t4) causes an error?

sorry I can't be more helpful,

Robert Dodier

Re: calculate complex integral of a sum

Raymond Toy — 2010-03-11T00:27:09

Not really clean, but this is how I would do it.  The sum in uniformly
convergent, so interchange the order of summation and integration.  Then
we have

integrate(1/(n^4+x^2),x,0,inf) -> %pi/2/n^2

after telling maxima that n is positive.   Then the sum is

load(simplify_sum);
simplify_sum(sum(%pi/2/n^2,n,1,inf)) -> %pi^3/12.

An aside:  I thought that nusum(1/n^2,n,1,inf) knew that the answer is
%pi^2/6, but it doesn't now.  Perhaps my memory is wrong.

I guess if there is a way to interchange summation and limits, then you
could have derived the right answer pretty easily too.  I don't know how
to tell maxima to interchange the order.

Ray

Re: Integrating gamma_incomplete

Richard Hennessy — 2010-03-10T23:48:25

These rules are not perfectly right completely I have found.  This can be done better in code.  I think tellsimp cannot 
be made to do it perfectly right so I am writing a Maxima code file that will do this and I can add it to integrate via 
abs_integrate's list of integration routines.

Rich


--------------------------------------------------
From: "Dieter Kaiser" <drdieterkaiser< at >web.de>
Sent: Tuesday, March 09, 2010 5:49 PM
To: "Richard Hennessy" <rich.hennessy< at >verizon.net>
Cc: <maxima< at >math.utexas.edu>
Subject: Re: [Maxima] Integrating gamma_incomplete

Re: calculate complex integral of a sum

Andrej Vodopivec — 2010-03-10T23:06:04

You can compute the same result with a little function which changes
the order of summation and limit:

(%i1) change_lim_sum(expr) :=
    if mapatom(expr) then expr
    else if inpart(expr, 0)=nounify(limit) and inpart(expr, 1,
0)=nounify(sum) then
        substpart(
            substpart(inpart(expr, 1, 1), expr, 1),
            inpart(expr, 1), 1)
    else map(change_lim_sum, expr)$
(%i2) integrate(sum(1/(n^4+x^2), n, 1, inf),x,0,inf);
(%o2) limit((sum(atan(x/n^2)/n^2,n,1,inf)),x,inf,minus)-limit(sum(atan(x/n^2)/n^2,n,1,inf),x,0,plus)
(%i3) change_lim_sum(%);
(%o3) (sum(limit(atan(x/n^2),x,inf,minus)/n^2,n,1,inf))-sum(limit(atan(x/n^2),x,0,plus)/n^2,n,1,inf)
(%i4) ev(%, limit, simpsum);
(%o4) %pi^3/12

Andrej

Re: Maxima Notes

Edwin Woollett — 2010-03-10T21:33:13

Hi again Price,  

when I said :

-------------------------
You can pursue what is going wrong right to the ultimate
  cause (something you cannot do with proprietary "for profit" code
   like Maxima). 
-------------------------------
of course I meant "for profit" code like Mathematica!!
Ted

Re: calculate .. integral of a sum

Janek Kozicki — 2010-03-10T21:12:17

Janek Kozicki said:     (by the date of Wed, 10 Mar 2010 22:11:07 +0100)



sorry about misleading title. It's not about complex numbers. Just a
"complex/difficult" problem.

calculate complex integral of a sum

Janek Kozicki — 2010-03-10T21:11:07

Hi,

integrate(sum(1/(n^4+x^2), n, 1, inf),x,0,inf);

by hand + using maxima to calculate some small parts of it,
I eventually reached the result, which is pi^3/12.

I wonder if it is possible to calculate in maxima straight off. Is it?

What I did, was replacing by hand arctan(0) with 0, separately
calculating limits and so on. Took a bit of time, and mostly I did it
myself on paper, just checking some parts with maxima. But still I'm
not even sure if my final result is correct ;)

question is - how to do it in a "clean" way in maxima?

Re: Maxima Notes

Edwin Woollett — 2010-03-10T18:56:05

 Hi Price,

  I see Maxima as the wave of the future.

1. It is free and will always be free. You can download as many copies
  as you want, so you don't have to get an expensive separate license for
  your office desktop, your laptop, and your home desktop (for example).
  You don't have to pay anoth big lump of cash every couple of years
  to renew the licenses every time Mathematica makes a major change.
  And if one of your computer motherboards die, you don't have to
  again pay out for a new license.

2. My experience with Mathematica ended with version 4.something, which I
   have on a separate desktop (remember, I can't move it without paying the
    piper!). As a retired professor who has moved out of the geographical
   area of his former university, thus making it harder to finagle in some 
way
    access to the campus license for mathematica for my home desktop, I
   would have to pay a hefty sum to get a license for one machine at home.
   (When I originally inquired, they wanted $1300. Several years later they
   started sending me "deals" at $700 or so. But once you climb on board
   the mathematica bandwagon, you will likely be paying regularly for the
    duration.)

2. I don't like the mathematica notebook concept. When I download a 
potentially
   interesting mathematica notebook, the most I can do with it is stare at 
the outline
   with the free reader. It won't work with my old version 4. And if I look 
at
    the text file code in the *.nb file, it is hard to get anything useful 
out of it.
   I much prefer Maxima code files which are text files which are readable
   and not encased in a casket of frufru "presentation graphics".

   As long as Maxima has the convenient XMaxima interface (and why should it
   every go away?) serious Maxima code files will be both readable and
   runnable ( of course bear in mind gradual syntax changes).

   I am presently writing chapters 12 and 13 of Maxima by Example, the first
   being examples of the use of explicit Dirac matrices in particle physics
   calculations , the second being examples of use of a symbolic Dirac
   algebra package, with comparisons (including timing trials) with the
   use of explicit Dirac matrix methods. (As you would expect, so far
   it is much faster to use explicit Dirac matrix methods.)  The important
   point here is that the code files are written in Maxima code (not  Lisp),
   and this will make it easier for Maxima users in high energy physics
   to adapt and extend the code for their own research purposes.

  This easy access to code, as will as the more natural syntax of Maxima
  (as compared with Mathematica) is an important advantage of Maxima,
  as well as the easy translation to Lisp (and compile as well) if this will
   speed up a particular section of work.

  3. Another important advantage of Maxima is its transparency. There
   are no black box routines which will defy your attempt to understand
   why your program is giving the wrong answers.  All the underlying
   source code for the core instructions come with every copy
   of Maxima. You can pursue what is going wrong right to the ultimate
  cause (something you cannot do with proprietary "for profit" code
   like Maxima). Sure, you might have to learn a little Lisp code
   eventually to track down the problem, but the Maxima developers
   available via the mailing list cheerfully offer expert advice on
   any serious question or hint of a bug in the core code.

4. Maxima is steadily improving. At present major improvements in the
   use of complex numbers and special functions are being incorporated,
   thanks to the tireless work of ambitious volunteers.  As the boomer
  generation begins the "great retirement" and pursues "encore careers",
  I expect many more smart volunteers will be available to add more
  and better features to the Maxima core and "third party" codes.

Best Wishes,
Ted Woollett
=======================



----- Original Message ----- 
From: "Price Kagey, PhD" <pricek< at >surfaceoptics.com>
To: <woollett< at >charter.net>
Sent: Friday, February 26, 2010 9:57 AM
Subject: Maxima Notes

Some issues (a bug?) with triangularize

Stefano Ferri — 2010-03-10T16:42:45

I was trying to solve a linear system (4 equations in 4 unknowns) by
reducing the complete matrix, and I came to this issue with
triangularize. When reducing the matrix in symbolic  form, one gets a
(wrong?) result, a different one (correct) if the triangularization is
made over numerical values.

This is the example: a system which, for h=-1, has 1 free unknown,
with infinite^1 solutions, with the following complete matrix:


(%i1) display2d:false;
(%o1) false

(%i2) M:matrix([h-1,h,h+2,h+1,1],[1-h,2,-h-2,1,1],[h-1,h,1,0,1],[0,-h-2,0,-2,1]);
(%o2) matrix([h-1,h,h+2,h+1,1],[1-h,2,-h-2,1,1],[h-1,h,1,0,1],[0,-h-2,0,-2,1])

(%i3) Mt:triangularize(M);
(%o3) matrix([h-1,h,1,0,1],[0,-h^2-h+2,0,2-2*h,h-1],
             [0,0,-h^3-2*h^2+h+2,-h^3-2*h^2+h+2,0],
             [0,0,0,-h^4-2*h^3+h^2+2*h,-3*h^3-6*h^2+3*h+6])

(%i4) ev(Mt,h=-1);
(%o4) matrix([-2,-1,1,0,1],[0,2,0,4,-2],[0,0,0,0,0],[0,0,0,0,0])

(%i5) Mr:triangularize(ev(M,h=-1));
(%o5) matrix([-2,-1,1,0,1],[0,-2,0,-2,-4],[0,0,0,2,-6],[0,0,0,0,0])

(%i9) rank(ev(Mt,h=-1));
(%o9) 2

(%i10)  rank(Mr);
(%o10) 3

(%i11) rank(ev(M,h=-1));
(%o11) 3


I have checked by hand, and Mt seems wrong (see the rank in the last
outputs). What's happening here? Is this a bug or I am missing
something?
The triangularization is correct if made over the only coefficient matrix.

Moreover, triangularize yelds to complicated expressions. See, in
example, the triangularization of the coefficient matrix above:


(%i20) Mc:submatrix(M,5);
(%o20) matrix([h-1,h,h+2,h+1],[1-h,2,-h-2,1],[h-1,h,1,0],[0,-h-2,0,-2])
(%i21) Mtc:triangularize(Mc);
(%o21) matrix([h-1,h,1,0],[0,-h^2-h+2,0,2-2*h],[0,0,h^3+2*h^2-h-2,h^2+h-2],
              [0,0,0,h^4+2*h^3-h^2-2*h])


while with some simple rows transformations, we get:


(%i12) Mc[2]:Mc[2]+Mc[1];
(%o12) [0,h+2,0,h+2]

(%i13) Mc[3]:Mc[3]-Mc[1];
(%o13) [0,0,-h-1,-h-1]

(%i14) Mc[4]:Mc[4]+Mc[2];
(%o14) [0,0,0,h]

%i15) Mc;
(%o15) matrix([h-1,h,h+2,h+1],[0,h+2,0,h+2],[0,0,-h-1,-h-1],[0,0,0,h])

The latter expression looks better to me (it has ony first order terms).


Can someone please check these results?

Thanks.
Stefano

Bug in integrate(bessel_j(4,x),x)

Richard Hennessy — 2010-03-10T01:22:07

I tried,

kill(all);
display2d:false;
 false
integrate(bessel_j(4,x),x);
 hypergeometric([5/2],[7/2,5],-x^2/4)*x^5/1920
integrate(%,x);
 hypergeometric([5/2],[7/2,5],-1/4)*x^6/11520
integrate(%,x);
 hypergeometric([5/2],[7/2,5],-1/4)*x^7/80640
integrate(%,x);
 hypergeometric([5/2],[7/2,5],-1/4)*x^8/645120
integrate(%,x);
 hypergeometric([5/2],[7/2,5],-1/4)*x^9/5806080

This is a bug.

Rich

Re: Bug in integrate(bessel_j(4,x),x)

Richard Hennessy — 2010-03-10T01:37:09

(%i1) build_info();

Maxima version: 5.20.1
Maxima build date: 21:25 12/14/2009
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8

Rich

--------------------------------------------------
From: "Richard Hennessy" <rich.hennessy< at >verizon.net>
Sent: Tuesday, March 09, 2010 8:22 PM
To: "Maxima List" <maxima< at >math.utexas.edu>
Subject: [Maxima] Bug in integrate(bessel_j(4,x),x)