[GAP Forum] Installing cvec package

[Alexander Konovalov]

Hello Marek,

On 31 Jul 2014, at 11:36, Marek Mitros <marek at mitros.org> wrote:

> 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.

Whatever will be the answer on the question above, you do not have to worry
much about the question below :) GAP for Windows is supplied with compiled 
cvec binary, which is built using the 32-bit Cygwin installation. So you're
running the 32-bit version of GAP anyhow. 

I have no information at the moment what will happen if one will install 
64-bit version of Cygwin and compile GAP and some packages there - hopefully 
it will work. If anyone would like to try, call these commands first:

./configure
make cygwin

and then to build some packages (with kernel modules) call

cd pkg/Browse
./configure
make
cd ..
cd cvec-*
./configure
make
cd ..
cd edim
./configure
make
cd ..
cd io-*
./configure
make
cd ..
cd orb-*
./configure
make

Best wishes
Alexander


> 
> 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
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