All subgroups of a permutation group

[rbeezer]

New method for permutation groups gets all the subgroups from GAP, via the conjugacy classes of subgroups.

Yes, this takes a very long time to compute and generates tons of output. A big warning in the docstring emphasizes this. But for small groups it is extremely instructive, well worth having, and way better than computing by hand. I've been wanting this for about two years now.

Apply trac_10685-permutation-group-subgroups-v3.patch

CC: @wdjoyner @dimpase

Component: group theory

Author: Rob Beezer

Reviewer: Dmitrii Pasechnik

Merged: sage-4.6.2.alpha4

Issue created by migration from https://trac.sagemath.org/ticket/10685

[rbeezer]

Author: Rob Beezer

[rbeezer]

comment:1

Attachment: trac_10685-permutation-group-subgroups.patch.gz

[dimpase]

comment:2

that's easy to review :)

[rbeezer]

comment:3

Replying to @dimpase:

that's easy to review :)

Thanks, Dima. That's gotta be a record for elapsed time. ;-)

[rbeezer]

comment:4

Hi Dima,

A second thought. I'm working with some other code for abelian groups, and there the relevant method is named just .subgroups(). I like that a bit better (and easier to find on tab-completion).

What do you think of calling this by the shorter, plural version?

Rob

[dimpase]

comment:5

Replying to @rbeezer:

Hi Dima,

A second thought. I'm working with some other code for abelian groups, and there the relevant method is named just .subgroups(). I like that a bit better (and easier to find on tab-completion).

What do you think of calling this by the shorter, plural version?

sounds actually better;
one can also think of eventually having
.subgroups(order=666,abelian=true), etc, etc...

Rob

[rbeezer]

Attachment: trac_10685-permutation-group-subgroups-v2.patch.gz

[rbeezer]

comment:6

Replying to @dimpase:

one can also think of eventually having
.subgroups(order=666,abelian=true), etc, etc...

Dima,

Yes, some filters like that would be a good idea (that I had not thought of).

v2 patch simple renames the function and makes the necessary changes in the doctest. Thanks for the extra work on this one.

Rob

[dimpase]

comment:7

Replying to @rbeezer:

Replying to @dimpase:

one can also think of eventually having
.subgroups(order=666,abelian=true), etc, etc...

Dima,

Yes, some filters like that would be a good idea (that I had not thought of).

v2 patch simple renames the function and makes the necessary changes in the doctest. Thanks for the extra work on this one.

OK, checked. It works.

Rob

[jdemeyer]

Reviewer: Dmitrii Pasechnik

[jdemeyer]

Work Issues: rebase

[jdemeyer]

comment:9

This needs to be rebased to sage-4.6.2.alpha2

[rbeezer]

Attachment: trac_10685-permutation-group-subgroups-v3.patch.gz

Rebased, apply only this one

[rbeezer]

Changed work issues from rebase to none

[rbeezer]

comment:10

Rebased patch on 4.6.2.alpha2 is the "v3" patch.

[jdemeyer]

Merged: sage-4.6.2.alpha4