ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Thu, 12 Mar 2015 08:45:47 +0100Using GAP package in Sagehttps://ask.sagemath.org/question/26163/using-gap-package-in-sage/I would like to use [this GAP package](http://www.gap-system.org/Manuals/pkg/wedderga/doc/chap1.html#X7DB566D5785B7DBC) to do some computations of representations, in particular [these commands](http://www.gap-system.org/Manuals/pkg/wedderga/doc/chap4.html). However, I want to use Sage and not GAP directly for various reasons (such as not having to switch back and forth between systems for where the computations come from).
An ideal "answer" to this question would give me
- Instructions for how to install this package in Sage (assuming Sage's GAP is new enough, which I think it is)
- How to get a group ring nicely with or without this package, from a given (Sage) group
- How to use `PrimitiveCentralIdempotentsByCharacterTable` from within Sage with this
- Ideally, how to apply a given representation to one of these idempotents
That's a tall order, probably, but I don't use the group theory stuff in Sage too often, so it would save me a lot of time if someone who "just knows" the syntax was able to help out. Thanks!Wed, 11 Mar 2015 23:50:53 +0100https://ask.sagemath.org/question/26163/using-gap-package-in-sage/Answer by vdelecroix for <p>I would like to use <a href="http://www.gap-system.org/Manuals/pkg/wedderga/doc/chap1.html#X7DB566D5785B7DBC">this GAP package</a> to do some computations of representations, in particular <a href="http://www.gap-system.org/Manuals/pkg/wedderga/doc/chap4.html">these commands</a>. However, I want to use Sage and not GAP directly for various reasons (such as not having to switch back and forth between systems for where the computations come from).</p>
<p>An ideal "answer" to this question would give me</p>
<ul>
<li>Instructions for how to install this package in Sage (assuming Sage's GAP is new enough, which I think it is)</li>
<li>How to get a group ring nicely with or without this package, from a given (Sage) group</li>
<li>How to use <code>PrimitiveCentralIdempotentsByCharacterTable</code> from within Sage with this</li>
<li>Ideally, how to apply a given representation to one of these idempotents</li>
</ul>
<p>That's a tall order, probably, but I don't use the group theory stuff in Sage too often, so it would save me a lot of time if someone who "just knows" the syntax was able to help out. Thanks!</p>
https://ask.sagemath.org/question/26163/using-gap-package-in-sage/?answer=26164#post-id-26164Hello,
For the first step: Just download the tarball, extract it into **$SAGE_ROOT/local/gap/latest/pkg/**. Then the following should work
$ sage -gap
GAP, Version 4.7.7 of 13-Feb-2015 (free software, GPL)
....
gap> LoadPackage("wedderga");
Loading Wedderga 4.3.3 (Wedderga)
...
true
At least, it works for me. Then, it can also be used from Sage
sage: gap('LoadPackage("wedderga")')
true
VincentThu, 12 Mar 2015 08:45:47 +0100https://ask.sagemath.org/question/26163/using-gap-package-in-sage/?answer=26164#post-id-26164