[GAP Forum] Installing cvec package

[Marek Mitros]

Hello,

I am trying to use the cvec package to have compressed matrices over GF(2).
But I do not see much difference - see below example log from my GAP
session.

I have installed newest GAP 4.7.5. I have 8 GB memory and system Windows 7
(64-bit). I have read in cvec package documentation that I should recompile
or configure it ... "For example you have to specify 32-bit or 64-bit mode
correctly!". But I don't know how to do it.

Regards,
Marek


gap> g:=AtlasGroup("B"); Print("Baby defined\n");

<matrix group of size 4154781481226426191177580544000000 with 2 generators>

Baby defined

gap> ge:=GeneratorsOfGroup(g); a:=ge[1]; b:=ge[2];

[ <an immutable 4370x4370 matrix over GF2>, <an immutable 4370x4370 matrix
over GF2> ]

<an immutable 4370x4370 matrix over GF2>

<an immutable 4370x4370 matrix over GF2>

gap>

gap> LoadPackage("cvec"); # compressed vectors and matrices over finite
fields

true

gap> ca:=CMat(a); cb:=CMat(b);

<cmat 4370x4370 over GF(2,1)>

<cmat 4370x4370 over GF(2,1)>

gap>

gap> MemoryUsage(a);

2519320

gap> MemoryUsage(ca);

2500728