Opened 10 years ago

Closed 10 years ago

#13943 closed enhancement (fixed)

Automorphisms of simplicial complexes

Reported by: chapoton Owned by: jhpalmieri
Priority: minor Milestone: sage-5.7
Component: algebraic topology Keywords: simplicial automorphism
Cc: Merged in: sage-5.7.beta1
Authors: Frédéric Chapoton Reviewers: Nathann Cohen
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by chapoton)

It would be good to have a method to compute the automorphism group of a simplicial complex.

This patch implements that.

And also a procedure to check wether two simplicial complexes are isomorphic

Attachments (1)

trac-13943-automorphism-group-of-simplical-fc.patch (4.8 KB) - added by chapoton 10 years ago.

Download all attachments as: .zip

Change History (15)

comment:1 Changed 10 years ago by chapoton

  • Status changed from new to needs_review

comment:2 Changed 10 years ago by chapoton

Better version, acting on vertices. Thanks, Nathann !

comment:3 Changed 10 years ago by chapoton

It would be good to have a method to compute the automorphism group of a simplicial complex.

This patch implements that.

And also a procedure to check wether two simplicial complexes are isomorphic.

comment:4 Changed 10 years ago by chapoton

  • Description modified (diff)

comment:5 Changed 10 years ago by ncohen

  • Status changed from needs_review to positive_review

Excellent ! Well, it seems good to go, it will certainly be useful eventually, and at the very least in #13888. Passes all tests, does its job :-)

Nathann

comment:6 Changed 10 years ago by jdemeyer

  • Milestone changed from sage-5.6 to sage-5.7
  • Reviewers set to Nathann Cohen

comment:7 Changed 10 years ago by jdemeyer

  • Status changed from positive_review to needs_work

Sphinx is unhappy:

/release/merger/sage-5.7.beta1/local/lib/python2.7/site-packages/sage/homology/simplicial_complex.py:docstring of sage.homology.simplicial_complex:3: WARNING: Bullet list ends without a blank line; unexpected unindent.

comment:8 Changed 10 years ago by chapoton

  • Status changed from needs_work to needs_review

I think I have corrected the sphinx issue in the new patch.

comment:9 Changed 10 years ago by ncohen

  • Status changed from needs_review to positive_review

Just checked again, and there's no warning... Sorry for that ^^;

Nathann

comment:10 Changed 10 years ago by jdemeyer

  • Status changed from positive_review to needs_work

On rosemary (RHEL 5.6 x86_64):

sage -t  --long -force_lib devel/sage/sage/homology/simplicial_complex.py
**********************************************************************
File "/home/buildbot/build/sage/rosemary-1/rosemary_full/build/sage-5.7.beta1/devel/sage-main/sage/homology/simplicial_complex.py", line 2914:
    sage: Z1.is_isomorphic(Z2, certify=True)
Expected:
    (True, {'a': 't', 1: 'e', 2: 4, 3: 'r'})
Got:
    (True, {'a': 'r', 2: 4, 3: 't', 1: 'e'})
**********************************************************************
File "/home/buildbot/build/sage/rosemary-1/rosemary_full/build/sage-5.7.beta1/devel/sage-main/sage/homology/simplicial_complex.py", line 2972:
    sage: Z.automorphism_group()
Expected:
    Permutation Group with generators [(3,4)]
Got:
    Permutation Group with generators [(1,4)]
**********************************************************************
File "/home/buildbot/build/sage/rosemary-1/rosemary_full/build/sage-5.7.beta1/devel/sage-main/sage/homology/simplicial_complex.py", line 2974:
    sage: Z.automorphism_group(translation=True)
Expected:
    (Permutation Group with generators [(3,4)], {'a': 4, 1: 1, 2: 2, 3: 3})
Got:
    (Permutation Group with generators [(1,4)], {'a': 1, 1: 2, 2: 3, 3: 4})
**********************************************************************

comment:11 Changed 10 years ago by chapoton

  • Status changed from needs_work to needs_review

I have tried to make more intrinsic doctests, and I hope they will pass.

comment:12 Changed 10 years ago by chapoton

new patch, with good tests

comment:13 Changed 10 years ago by ncohen

  • Status changed from needs_review to positive_review

Well, it looks good to me again. The first dictionary in the doctests should not be a problem as the hash function of an integer is the integer itself, and the other tests are now isomorphism tests, returning True/False?.

Sooooooooo I guess it's good to go again !

Nathann

comment:14 Changed 10 years ago by jdemeyer

  • Merged in set to sage-5.7.beta1
  • Resolution set to fixed
  • Status changed from positive_review to closed
  • Summary changed from automorphisms of simplicial complexes to Automorphisms of simplicial complexes
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