Automorphism group of finite abelian groups.

[simonbrandhorst]

This ticket implements the automorphism group of finite abelian groups.
Methods should include:

• generators
• subgroups
• it is essentially a matrix group so the implementation can reflect that.
• an action on the elements of the underlying abelian group.
• in gap there is a method AbelianGroupAutomorphismGroup. We could wrap that.

Depends on #24521
Depends on #24590

Component: linear algebra

Author: Simon Brandhorst

Branch/Commit: c6b1d03

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/24087

[simonbrandhorst]

Dependencies: #24521

[simonbrandhorst]

Branch: u/sbrandhorst/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_

[simonbrandhorst]

Commit: cc72b1a

[simonbrandhorst]

New commits:

f9af766	First undocumented prototype
0b13ad7	Documentation an bugfixes.
74234d4	Documentation and removed hash method for AbelianGroup_gap
7ad95ea	Abelian groups with gap are not independent beings of the sage abelian groups
99296dc	Reworked pickling. Reference builds now.
c3bd7a1	Added an example
4d2fbe0	Added method is_subgroup_of.
cc72b1a	First version including working doc.

[sagetrac-git]

Changed commit from cc72b1a to a368cf2

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

1695bd8	bugfixes
c846a0e	Changed printing of elements and fixed doctests.
ec2c011	Doctest `_gap_init_` is now optional gap_packages
fc8cc83	Merge branch 't/24521/abelian_groups_with_gap' into t/24087/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_
a368cf2	Documentation

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d671646

Conversion from FGP_morphism

[sagetrac-git]

Changed commit from a368cf2 to d671646

[simonbrandhorst]

Changed dependencies from #24521 to #24521, #24590

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

61236d7

Merge branch 'develop' of git://trac.sagemath.org/sage into t/24087/automorphism_group_of_finite_abelian_groups_

[sagetrac-git]

Changed commit from d671646 to 61236d7

[sagetrac-git]

Changed commit from 61236d7 to 707824c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

707824c

replaced is_endomorphism in conversions

[sagetrac-git]

Changed commit from 707824c to a554f99

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

884ad23	Merge branch 'develop' of git://trac.sagemath.org/sage into t/24087/automorphism_group_of_finite_abelian_groups_
42182d0	Merge branch 'develop' of git://trac.sagemath.org/sage into t/24521/abelian_groups_with_gap
4e2897a	Fixing bugs and doing some cleanup.
23f489a	Improved exponents()
59b11ed	added # optional gap_packages to fix doctest
477b66d	Merge branch 'develop' into t/24521/abelian_groups_with_gap
fda9cdc	Merge commit '477b66d14b8eceb0ab2d91a6aa36be646dd16526' of git://trac.sagemath.org/sage into t/24087/automorphism_group_of_finite_abelian_groups_
a554f99	Small changes.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d65e99b	Merge branch 'develop' into t/24087/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_
39a3d39	Merge branch 'u/sbrandhorst/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_' of git://trac.sagemath.org/sage into t/24087/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_
3f410a8	Cosmetics

[sagetrac-git]

Changed commit from a554f99 to 3f410a8

[tscrim]

Changed commit from 3f410a8 to c4e3299

[tscrim]

Author: Simon Brandhorst

[tscrim]

Changed branch from u/sbrandhorst/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_ to u/tscrim/automorphism_group_finite_abelian_groups_gap-24087

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

comment:12

I made one non-trivial change: I removed the @cached_method from the automorphism_group() since the caching is (better) handled by the UniqueRepresentation.

The rest of my changes are just some simple cleanup of the doc and code.

If my changes look good, then positive review.

---

New commits:

5e3e543	Merge branch 'u/sbrandhorst/endomorphisms_ring_and_automorphism_group_of_finite__additive__abelian_groups_' of git://trac.sagemath.org/sage into u/tscrim/automorphism_group_finite_abelian_groups_gap-24087
0c212d2	Do not use @cached_method for automorphism_group().
c4e3299	Some cleanup and other minor tweaks.

[simonbrandhorst]

Changed branch from u/tscrim/automorphism_group_finite_abelian_groups_gap-24087 to u/sbrandhorst/automorphism_group_finite_abelian_groups_gap-24087

[sagetrac-git]

Changed commit from c4e3299 to 5db61c2

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

5db61c2

Fixed indentation.

[simonbrandhorst]

Changed commit from 5db61c2 to c4e3299

[simonbrandhorst]

comment:15

Thank you for the cleanup. The doc did not build due to a missing space.
I added that and now it builds.

[simonbrandhorst]

Changed branch from u/sbrandhorst/automorphism_group_finite_abelian_groups_gap-24087 to u/tscrim/automorphism_group_finite_abelian_groups_gap-24087

[vbraun]

comment:16

See patchbot

[dochtml] OSError: [groups ] /opt/sage/local/lib/python2.7/site-packages/sage/groups/abelian_gps/abelian_aut.py:docstring of sage.groups.abelian_gps.abelian_aut.AbelianGroupAutomorphismGroup_gap:9: WARNING: Bullet list ends without a blank line; unexpected unindent.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

c6b1d03

Fixing minor doc issue.

[sagetrac-git]

Changed commit from c4e3299 to c6b1d03

[tscrim]

comment:18

Whoops, mea culpa. Fixed and verified the doc now builds.

[vbraun]

Changed branch from u/tscrim/automorphism_group_finite_abelian_groups_gap-24087 to c6b1d03