[LON-CAPA-users] looking for linear algebra library

Stefan Bisitz lon-capa-users@mail.lon-capa.org
Tue, 20 Nov 2007 16:51:45 +0100


> Jay Sullivan wrote:
> 
> > Okay, maybe I spoke to soon. Is there a character limit on the 
> output of &cas?
> > 
> > When I try the following, the output seems truncated:
> > 
> > <script type="loncapa/perl">
> > $s= 'maxima';
> > $str = &cas($s,'invert(matrix([10,-4],[1,0.5]))');
> > </script>
> > $str
> > 
> > The output on the screen is:
> > matrix([0.05555555555556,0.44444444444444],


Peter Riegler wrote:
> Here ist what maxima does:
> (%i34) invert(matrix([10,-4],[1,0.5]))
> ;
> (%o34) matrix([0.055555555555556,0.44444444444444],
>               [-0.11111111111111,1.111111111111111])
> (%i35) invert(matrix([10,-4],[1,1/2]));
> (%o35) matrix([1/18,4/9],[-1/9,10/9])
> (%i36)
> 
> I have the uneasy feeling that we might have a bug here in 
> lonmaxima (the part of loncapa which provides the interface
> to maxima). I faintly remember to have fixed something
>  similar. I have to check.
> 
> Thanks for pointing out.

Peter, I guess that you mean our bugfix in lonmaxima (not
lonmaxima.pm!). This fixed the issues with multiple output lines which
came from maxima. I checked my test code which still works fine with
official release lonmaxima 1.36 in LON-CAPA 2.5.3.

Guy, maybe you have any idea?

Stefan Bisitz