Opened 8 years ago

Closed 8 years ago

Last modified 8 years ago

#15189 closed defect (fixed)

LinearMatroid.is_field_isomorphic fails on some occasions

Reported by: Stefan Owned by:
Priority: major Milestone: sage-5.12
Component: matroid theory Keywords:
Cc: yomcat Merged in: sage-5.12.rc1
Authors: Stefan van Zwam Reviewers: Michael Welsh
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by Stefan)

The following code should return False:

sage: M = Matroid(ring=GF(5), reduced_matrix=[[1,0,3],[0,1,1],[1,1,0]])
sage: N = Matroid(ring=GF(5), reduced_matrix=[[1,0,1],[0,1,1],[1,1,0]])
sage: M.is_field_isomorphic(N)
True

Indeed:

sage: any(M.is_field_isomorphism(N, p) for p in Permutations(range(6)))
False

The cause is a recursive call gone wrong in set_system.pyx.

apply trac_15189_field_isom_fix.patch​

Attachments (1)

trac_15189_field_isom_fix.patch (1.5 KB) - added by Stefan 8 years ago.

Download all attachments as: .zip

Change History (14)

comment:1 Changed 8 years ago by Stefan

  • Branch set to u/Stefan/ticket/15189
  • Created changed from 09/12/13 16:50:53 to 09/12/13 16:50:53
  • Modified changed from 09/12/13 16:50:53 to 09/12/13 16:50:53

comment:2 Changed 8 years ago by Stefan

  • Status changed from new to needs_review

comment:3 Changed 8 years ago by Stefan

  • Cc yomcat added

comment:4 Changed 8 years ago by yomcat

How do I review this? I can't seem to get the Branch thing working (when I click on it, I either need to browse through a file system too much to find the changes, or get a blank page).

comment:5 Changed 8 years ago by Stefan

By clicking on (Commits) in the Branch field, and selecting the appropriate diffs (topmost versus second from top) you can view my changes.

Otherwise, I'm still learning this whole process. Apparently the Branch link being colored red is a bad thing (it was green when I first uploaded this)...

For the record, to create this patch I followed instructions here:

http://trac.sagemath.org/wiki/QuickStartSageGit

And then here:

http://sagemath.github.io/git-developer-guide/walk_through.html

comment:6 Changed 8 years ago by Stefan

  • Branch u/Stefan/ticket/15189 deleted
  • Description modified (diff)
  • Status changed from needs_review to needs_work

Changed 8 years ago by Stefan

comment:7 follow-up: Changed 8 years ago by Stefan

  • Authors set to Stefan van Zwam
  • Description modified (diff)
  • Status changed from needs_work to needs_review

Ok, I chickened out of the Git development process for now and uploaded a good, old-fashioned patch.

comment:8 in reply to: ↑ 7 Changed 8 years ago by yomcat

  • Reviewers set to Michael Welsh
  • Status changed from needs_review to positive_review

Replying to Stefan:

Ok, I chickened out of the Git development process for now and uploaded a good, old-fashioned patch.

I was going to get round to the git stuff eventually... :)

All good now.

comment:9 Changed 8 years ago by jdemeyer

  • Milestone changed from sage-5.12 to sage-5.13

comment:10 Changed 8 years ago by Stefan

Really? It's just a one-line fix (plus doctest) in a quite isolated part of Sage...

comment:11 Changed 8 years ago by jdemeyer

  • Milestone changed from sage-5.13 to sage-5.12

comment:12 Changed 8 years ago by jdemeyer

  • Merged in set to sage-5.12.rc1
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:13 Changed 8 years ago by Stefan

Awesome, thanks!

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