Opened 8 years ago

Closed 8 years ago

#13399 closed defect (fixed)

Fixes to symmetric functions

Reported by: aschilling Owned by: sage-combinat
Priority: major Milestone: sage-5.4
Component: combinatorics Keywords: symmetric functions
Cc: sage-combinat, zabrocki Merged in: sage-5.4.beta2
Authors: Anne Schilling, Mike Zabrocki Reviewers: Mike Zabrocki, Anne Schilling
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: #13404 Stopgaps:

Description (last modified by zabrocki)

This patch implements the following fixes to symmetric functions:

  • HL creation operator for k-Schur functions
  • it fixes omega for k-Schur functions for generic t
  • it changes the multiplication for k-Schur functions for generic t, so that the result stays in the k-bounded subspace if possible and lifts to symmetric functions otherwise
  • it moves coproduct_by_coercion to SymmetricFunctionAlgebra_generic and inserts a coproduct function in KBoundedSubspaceBases, ElementMethods?
  • it fixes the coersion between the Jack P and Pq basis; this was previously extremely slow, for example for
        sage: Sym = SymmetricFunctions(FractionField(QQ['t']))
        sage: Qp = Sym.jack().Qp()
        sage: P = Sym.jack().P()
        sage: P(Qp[2,1])
        ((-192*t^3+192*t^2-192*t+192)/(-64*t^3-224*t^2-224*t-64))*JackP[1, 1, 1]
        + ((128*t^2-64*t+80)/(64*t^2+64*t+16))*JackP[2, 1] + ((8*t-8)/(8*t+4))*JackP[3]
    
  • it fixes the coproduct for Jack symmetric functions

Apply:

Attachments (1)

trac_13399-sf-as.3.patch (38.2 KB) - added by jdemeyer 8 years ago.
same patch with minor doc changes

Download all attachments as: .zip

Change History (20)

comment:1 Changed 8 years ago by aschilling

  • Description modified (diff)

comment:2 Changed 8 years ago by nthiery

Speaking of fixes/improvements for symmetric functions: the current code is not perfectly consistent for the naming of the bases:

sage: S = SymmetricFunctions(QQ['q,t'].fraction_field())
sage: S.s()
Symmetric Function Algebra over Fraction Field of Multivariate Polynomial Ring in q, t over Rational Field, Schur symmetric functions as basis
sage: S.macdonald().P()
Symmetric Functions over Fraction Field of Multivariate Polynomial Ring in q, t over Rational Field in the realization MacdonaldPolynomials_p

And indeed in the code, S.s()._repr_ comes from SymmetricFunctionAlgebra_classical, where as S.macdonald().P()._repr_ comes from generic with_realization code.

What about moving (in this ticket, or later), the _repr_ from SymmetricFunctionAlgebra_classical to SymmetricFunctionsBases??

A bit of fiddling with ._basis might be needed to get the string 'Macdonald P symmetric functions' right, but this should not be too bad.

Cheers,

Nicolas

PS: as a side effect, this would help me a bit with my functorial construction patch, as it currently breaks the naming of the macdo/llt/hl basis, and would not anymore with the changes above.

comment:3 follow-up: Changed 8 years ago by aschilling

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

comment:4 in reply to: ↑ 3 Changed 8 years ago by aschilling

Hi Mike,

I made all changes we discussed by e-mail. Could you have a look?

Anne

comment:5 follow-up: Changed 8 years ago by zabrocki

  • Status changed from needs_review to positive_review

All tests pass and the documentation looks good. Nicolas, we can address the __repr__ changes in another patch. -Mike

Last edited 8 years ago by zabrocki (previous) (diff)

comment:6 in reply to: ↑ 5 ; follow-up: Changed 8 years ago by aschilling

Thank you, Mike! Same comments as on 12140.

comment:7 in reply to: ↑ 6 Changed 8 years ago by aschilling

Removed trailing white spaces.

comment:8 Changed 8 years ago by aschilling

  • Dependencies set to #5457

comment:9 Changed 8 years ago by zabrocki

  • Status changed from positive_review to needs_work

After discussion, another addition to make will be coproduct method on k-Schur bases.

comment:10 Changed 8 years ago by zabrocki

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

I implemented coproduct on k-Schur functions. This required moving coproduct_by_coercion to the class SymmetricFunctionAlgebra_generic . Please test and review.

comment:11 follow-up: Changed 8 years ago by aschilling

  • Authors changed from Anne Schilling to Anne Schilling, Mike Zabrocki
  • Description modified (diff)
  • Reviewers changed from Mike Zabrocki to Mike Zabrocki, Anne Schilling

comment:12 in reply to: ↑ 11 Changed 8 years ago by aschilling

Hi Mike,

Thanks for the addition! I made some more changes to the doc explanations (there was still a reference to monomial symmetric functions even though coproduct_by_coercion was moved to sfa.py). I also added some further tests for k-Schurs and LLTs. Both patches are now folded, so please only

Apply: trac_13399-sf-as.patch

All tests pass on sage_5.3.rc0 + two additional 5457 patches. No idea what the current version of sage is that we are supposed to test against!

Best,

Anne

comment:13 follow-up: Changed 8 years ago by aschilling

  • Dependencies changed from #5457 to #13404

comment:14 in reply to: ↑ 13 Changed 8 years ago by aschilling

Rebased with respect to #13404. More additions regarding Jack polynomials are pending!

comment:15 follow-up: Changed 8 years ago by aschilling

  • Description modified (diff)

comment:16 in reply to: ↑ 15 Changed 8 years ago by aschilling

Hi Mike,

I folded the previous 13399 patch with the changes to jack.py. For me all tests pass and the documentation looks good. Please set a positive review if you are satisfied!

Anne

comment:17 follow-up: Changed 8 years ago by zabrocki

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

I changed two minor things in the doc strings indicating that coercion was done through the homogeneous basis. All doc tests pass on sage-5.3.rc1 + dependency patches. It looks good and I give it a positive review.

comment:18 in reply to: ↑ 17 Changed 8 years ago by aschilling

Apply: trac_13399-sf-as.3.patch

Changed 8 years ago by jdemeyer

same patch with minor doc changes

comment:19 Changed 8 years ago by jdemeyer

  • Merged in set to sage-5.4.beta2
  • Resolution set to fixed
  • Status changed from positive_review to closed
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