Opened 8 years ago

Closed 8 years ago

#14163 closed enhancement (fixed)

add counit method to QSym

Reported by: saliola Owned by: sage-combinat
Priority: major Milestone: sage-5.8
Component: combinatorics Keywords: qsym, hopf algebras
Cc: zabrocki Merged in: sage-5.8.beta1
Authors: Mike Zabrocki, Franco Saliola Reviewers: Franco Saliola, Mike Zabrocki
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by saliola)

The Hopf algebra of quasisymmetric functions is missing the counit method.

sage: QSym = QuasiSymmetricFunctions(QQ)
sage: F = QSym.Fundamental()
sage: F.counit

Without the counit, _test_antipode at #14161 fails for QSym

Apply: trac_14163_add_counit_qsym-fs.patch

Attachments (1)

trac_14163_add_counit_qsym-fs.patch (3.5 KB) - added by saliola 8 years ago.
apply only this patch

Download all attachments as: .zip

Change History (7)

comment:1 Changed 8 years ago by zabrocki

  • Authors set to Mike Zabrocki
  • Status changed from new to needs_review

Added counit_on_basis to the ParentMethods of the Bases class in QSym. This is a copy of what is in NSym.

Changed 8 years ago by saliola

apply only this patch

comment:2 Changed 8 years ago by saliola

  • Authors changed from Mike Zabrocki to Mike Zabrocki, Franco Saliola
  • Description modified (diff)
  • Reviewers set to Franco Saliola, Mike Zabrocki

Since the code is identical to that of NSym, I put the method in ParentMethods for bases of both algebras. Attached it an updated patch. Mike, if you like the change, then set this to positive review.

comment:3 Changed 8 years ago by nthiery

This really should be added to GradedConnectedHopfAlgebrasWithBasis?. But we don't have this category yet (it will be easy when the functorial construction patch will be there). So good for now, but please open a ticket to remind us to create this category and put the counit there!


comment:4 Changed 8 years ago by zabrocki

  • Status changed from needs_review to positive_review

comment:5 Changed 8 years ago by jdemeyer

  • Work issues implement the counit deleted

comment:6 Changed 8 years ago by jdemeyer

  • Merged in set to sage-5.8.beta1
  • Resolution set to fixed
  • Status changed from positive_review to closed
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