[GAP Forum] Two questions

[Mathieu Dutour]

>> 2) I would like to use linear programming in GAP. Before I start 
>> implementing the simplex method in GAP, I would like to ask if anybody 
>> has done it before? This could save me some time. :-)
>> 
>> Actually, I already made a very simple GAP interface to Maxima to solve 
>> linear programs. If somebody is interested, he/she can contact me. 
>> Unfortunately, I am not impressed by Maxima's speed.
You might be interested by my GAP package "polyhedral" available from
http://www.liga.ens.fr/~dutour/Polyhedral/index.html

which would contain all you need. The problem is that there is no
manual, there is a lot of external programs to compile. But overall,
it might fit your needs and much more.

This is basically the way: write files, call external program, use perl
script to convert to GAP readable and load the result back.

>> BTW, I am interested in any kind of implementation of fast exact 
>> rational simplex method.
cdd and lrs are such.
But this all depends on what you really need.