Opened 7 years ago

Closed 7 years ago

#14348 closed enhancement (fixed)

Implement cycle index of combinatorial logarithm (virtual) species

Reported by: agd Owned by: agd
Priority: major Milestone: sage-5.10
Component: combinatorics Keywords: cycle index, species
Cc: sage-combinat Merged in: sage-5.10.beta1
Authors: Andrew Gainer-Dewar Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description (last modified by chapoton)

The semiring of species can be completed to form the ring of "virtual species", which are certain equivalence classes of formal differences of species. Among other benefits, this allows the "compositional inverse" of a species to be defined. It turns out that virtual species have well-defined cycle index series (which may have negative coefficients).

This patch adds code to compute the cycle index of the "combinatorial logarithm" virtual species, which is the compositional inverse of the species of nonempty sets. Among other things, this can be used to extract the cycle index of a species of "connected F-structures" from the cycle index for the species F. (The standard example is the case of the species G of simple graphs.)

I believe this code is functional and complete.

Apply:

Attachments (1)

trac_14348_combinatorial_logarithm.patch (5.2 KB) - added by agd 7 years ago.

Download all attachments as: .zip

Change History (16)

comment:1 Changed 7 years ago by agd

  • Component changed from PLEASE CHANGE to combinatorics
  • Type changed from PLEASE CHANGE to enhancement

comment:2 Changed 7 years ago by agd

  • Status changed from new to needs_review

comment:3 Changed 7 years ago by chapoton

  • Every function must be doc-tested. You should add doc and examples to auxiliary functions too.

comment:4 Changed 7 years ago by agd

I've uploaded a new version for the patch which includes docstrings and EXAMPLES:: doctests for all methods.

Thanks for the feedback!

comment:5 Changed 7 years ago by chapoton

  • Description modified (diff)
  • Status changed from needs_review to positive_review

If you are happy with the little changes in my review patch, you can set a positive review in my behalf.

comment:6 Changed 7 years ago by chapoton

  • Status changed from positive_review to needs_work

comment:7 Changed 7 years ago by chapoton

  • Status changed from needs_work to needs_review

comment:8 Changed 7 years ago by agd

  • Status changed from needs_review to positive_review

Thanks for the patch! As you can see, I don't quite have the hang of the doctest system yet.

comment:9 Changed 7 years ago by jdemeyer

  • Reviewers set to Frédéric Chapoton

comment:10 Changed 7 years ago by jdemeyer

  • Status changed from positive_review to needs_work

The patch is not a proper patch file, patches should be generated using hg export tip. Also make sure you have .hgrc set up, see http://sagemath.org/doc/developer/

comment:11 Changed 7 years ago by agd

Whoops! Thanks for the tip.

I've added a new version of the patch created using "hg export tip". This version includes the adjustments suggested by chapoton. (Is this correct form? Should I leave those changes in a separate patch?)

comment:12 Changed 7 years ago by agd

  • Status changed from needs_work to needs_review

comment:13 Changed 7 years ago by chapoton

  • Description modified (diff)

yes, its ok (but it was not necessary) to include my changes in your patches.

for the patchbot:

apply trac_14348_combinatorial_logarithm.patch

Last edited 7 years ago by chapoton (previous) (diff)

comment:14 Changed 7 years ago by chapoton

  • Status changed from needs_review to positive_review

looks good to me, positive review

comment:15 Changed 7 years ago by jdemeyer

  • Merged in set to sage-5.10.beta1
  • Resolution set to fixed
  • Status changed from positive_review to closed
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