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

Peter Riegler lon-capa-users@mail.lon-capa.org
Tue, 20 Nov 2007 18:02:09 +0100

Jay,

in addition to Stefan's email: I have tested your code on our server
running version 2.5.3 of loncapa. There it works as it should. So I
guess you are using a pre-2.5.3-version or even pre-2.5.2 (that's what I
remember the bugfix has been released).

Peter

Stefan Bisitz wrote:

>>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
>
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--
Peter Riegler
Fachhochschule Braunschweig/Wolfenbüttel
Salzdahlumer Str. 46/48, 38302 Wolfenbüttel
Tel. +49 5331 939 6314, Fax. +49 5331 939 6002
email: p.riegler@fh-wolfenbuettel.de
http://public.rz.fh-wolfenbuettel.de/~riegler