#15094: QSym: internal coproduct, Frobenius, lambda-of-monomials, documentation
fixes
-------------------------------------+-------------------------------------
Reporter: darij | Owner:
Type: enhancement | Status: positive_review
Priority: major | Milestone: sage-5.12
Component: combinatorics | Resolution:
Keywords: sage-combinat, | Merged in:
qsym, quasi-symmetric functions | Reviewers: Mike Zabrocki, Travis
Authors: Darij Grinberg | Scrimshaw
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: #14775, #13505 | Stopgaps:
-------------------------------------+-------------------------------------
Changes (by darij):
* status: needs_review => positive_review
Old description:
> The patch does the following:
>
> - Implement the internal coproduct on QSym, the ring of quasi-symmetric
> functions. (There is no reasonable internal product on QSym.)
>
> - Implement the Frobenius=Adams endomorphisms on QSym. (There seems to be
> no Verschiebung.)
>
> - Add a method that computes the lambda-ring operations at the monomial
> basis elements. This will be very useful later when we implement
> Hazewinkel's polynomial basis.
>
> - Fix errors in the docstrings in {{{sage/combinat/ncsf_qsym/qsym.py}}}.
> The fundamental basis was defined incorrectly. The coproduct was claimed
> to be inherited from the polynomial ring (which was wrong). The finitely-
> many-variables case was moved from the beginning to the end of the
> introduction because it is not implemented in Sage. Shuffles were
> replaced by stuffles in the definition of the product on the monomial
> basis.
>
> There are some obvious ways to go from here (corresponding changes on
> NSym, the Hazewinkel basis, possibly optimizing the dual immaculates
> etc.) but I am done for now.
>
> The #14775 dependency is only because of a reference in the docstrings.
>
> Apply:
>
> * [attachment:trac_15094-rebased-QSym-dg.patch]
> * [attachment:trac_15094-review-ts.patch]
New description:
The patch does the following:
- Implement the internal coproduct on QSym, the ring of quasi-symmetric
functions. (There is no reasonable internal product on QSym.)
- Implement the Frobenius=Adams endomorphisms on QSym. (There seems to be
no Verschiebung.)
- Add a method that computes the lambda-ring operations at the monomial
basis elements. This will be very useful later when we implement
Hazewinkel's polynomial basis.
- Fix errors in the docstrings in {{{sage/combinat/ncsf_qsym/qsym.py}}}.
The fundamental basis was defined incorrectly. The coproduct was claimed
to be inherited from the polynomial ring (which was wrong). The finitely-
many-variables case was moved from the beginning to the end of the
introduction because it is not implemented in Sage. Shuffles were replaced
by stuffles in the definition of the product on the monomial basis.
There are some obvious ways to go from here (corresponding changes on
NSym, the Hazewinkel basis, possibly optimizing the dual immaculates etc.)
but I am done for now.
The #14775 dependency is only because of a reference in the docstrings.
Apply:
* [attachment:trac_15094-rebased-QSym-dg.patch]
* [attachment:trac_15094-review-ts.patch]
* [attachment:trac_15094-last-changes-dg.patch]
--
Comment:
Nice changes; here's just a couple of typos fixed. I'm setting it to
positive review, OK?
For patchbot:
Apply: trac_15094-rebased-QSym-dg.patch, trac_15094-review-ts.patch
trac_15094-last-changes-dg.patch
--
Ticket URL: <http://trac.sagemath.org/ticket/15094#comment:18>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/groups/opt_out.
