Changes between Version 1 and Version 5 of Ticket #5457


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Timestamp:
07/15/12 04:38:50 (8 years ago)
Author:
aschilling
Comment:

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  • Ticket #5457

    • Property Authors changed from to Mike Zabrocki, Anne Schilling
    • Property Cc sage-combinat added
    • Property Summary changed from Refactor symmetric functions to Refactor symmetric functions and k-bounded subspace
    • Property Report Upstream changed from to N/A
    • Property Keywords symmetric functions sd38 sd40 added
    • Property Reviewers changed from to Dan Bump, Franco Saliola
  • Ticket #5457 – Description

    v1 v5  
    1 Refactor symmetric functions to:
    2  - use a single entry point, as in MuPAD-Combinat. Something like:
    3       -  S = SymmetricFunctions(field)
    4       -  S.schur
    5       -  S.jack(t).P
    6       -  S.macdonald(t,q).Q
    7       -  S.kSchur(3).H
    8  - use the coercion framework
    9  - use the category framework
     1This patch restructures the implementation of symmetric functions in sage
     2
     3The new implementation makes use of multiple realizations and the category
     4framework. The new access to symmetric functions is via
     5{{{
     6sage: Sym = SymmetricFunctions(QQ)
     7}}}
     8
     9Further new features that are implemented:
     10
     11- The ring of symmetric functions is now endowed with a Hopf algebra structure.
     12  The coproduct and antipode are implemented (which were missing before).
     13
     14- A tutorial on how to use symmetric functions in sage is included at the
     15  beginning of sf.py which is also accessible via
     16{{{
     17sage: SymmetricFunctions??
     18}}}
     19
     20- Symmetric functions should now work a lot better with respect to
     21  specializing parameters like `q` and `t` for Hall-Littlewood, Jack
     22  and Macdonald symmetric functions. Certain functionalities before
     23  this change were broken or not possible.
     24
     25- Documentation was added to LLT polynomials (which had very sparse documentation
     26  previously).
     27
     28- The `k`-bounded subspace of the ring of symmetric function was implemented.
     29  The `k`-Schur functions now live in the `k`-bounded subspace rather than
     30  in the ring of symmetric functions as before.
     31
     32This patch gained tremendously by the tutorial on symmetric functions written
     33by Jason Bandlow and Nicolas Thiery, a draft on the `k`-bounded subspace by
     34Jason Bandlow, and code multiple realizations written by Franco Saliola.
    1035
    1136See also:http://groups.google.com/group/sage-devel/msg/a49f3288fca1b75c