[GAP Forum] Construct list of subgroups fixed size

[Burkhard Höfling]

On 2011-06-08, at 14:53 , Максим wrote:

> Hello!
> 
> I have a big group G (size is 5^6*2 > 30000). I wanted to construct a list of subgroups but failed because of leak of memory. 


Since your group G is solvable, you should preferably work in an isomorphic pc group (via `IsomorphismPcGroup').

You can then use `SubgroupsSolvableGroup'  to compute the subgroups (up to conjugacy). In order to compute only the subgroups of a given order (up to conjugacy), you can use `SubgroupsSolvableGroup' together with `ExactSizeConsiderFunction'. All these functions are explained in the GAP manual.

Note that you may still run out of memory, since the Sylow 5-subgroup may contain lots of subgroups. 

If this doesn't work for you, it would be best if you could send the GAP code to construct your group.

Cheers

Burkhard.