Opened 4 years ago

Closed 4 years ago

#25067 closed enhancement (fixed)

Implement quantum group q-numbers

Reported by: tscrim Owned by:
Priority: major Milestone: sage-8.2
Component: algebra Keywords: quantum groups, q-analogs
Cc: sage-combinat, darij, aschilling, bsalisbury01, andrew.mathas Merged in:
Authors: Travis Scrimshaw Reviewers: Darij Grinberg
Report Upstream: N/A Work issues:
Branch: e0893e0 (Commits, GitHub, GitLab) Commit: e0893e046355d1fd32a3d49fcce0a163d32ab354
Dependencies: Stopgaps:

Status badges

Description

Split off of #15508 for better granularity and to use it to build other tickets. Implements [n]_q, [n]_q! and q-binomials that appear in quantum groups.

Change History (7)

comment:1 Changed 4 years ago by tscrim

  • Branch set to public/quantum_groups/q_numbers-25067
  • Commit set to 67c6ba01bb525a68ed88a5bfc4623d23f9a249ab
  • Status changed from new to needs_review

New commits:

67c6ba0Adding q-analogs used in quantum groups.

comment:2 Changed 4 years ago by git

  • Commit changed from 67c6ba01bb525a68ed88a5bfc4623d23f9a249ab to e908d5996b85d0897794bd15b97456f5afcc6722

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

e908d59Adding q-analogs used in quantum groups.

comment:3 Changed 4 years ago by git

  • Commit changed from e908d5996b85d0897794bd15b97456f5afcc6722 to e0893e046355d1fd32a3d49fcce0a163d32ab354

Branch pushed to git repo; I updated commit sha1. New commits:

e0893e0documentation improvements

comment:4 Changed 4 years ago by tscrim

  • Reviewers set to Darij Grinberg
  • Status changed from needs_review to positive_review

Discussed with Darij and says good modulo his changes, which LGTM. So positive review. Thank you!

comment:5 Changed 4 years ago by andrew.mathas

Sorry to be late to the party but are you aware of combinat/q_analogues.py? In particular, this module provides functions q_int, q_factorial and q_binomial (among others). I have not been through this ticket in detail but comparing the q_int function in this ticket appears to be less general than the existing function because, in q_analogues.py, q_int(n) allows n to be positive or negative whereas the q_int function in this ticket requires n to be non-negative. On the other hand, the quantum integer that the existing q_int returns is different to the one in this ticket.

I am not sure how much this ticket overlaps with the code that is already in sage but some one should check. At a minimum, I think that there should be some documentation links between this code and the pre-existing code and, arguably, the code should be merged so that we don't have code providing similar functionality in different places. Different function names, or a more general syntax that allows one to choose between the different quantum integers, should also be considered.

Annoyingly, the q_int defined in q_analogues.py is the natural quantum integer to use in Hecke algebras whereas the q_int defined in this ticket is what is required in the quantum group setting...so both are needed.

As I have not read through all of the code I won't set this back to needs work but my feeling is that it does need more work.

Last edited 4 years ago by andrew.mathas (previous) (diff)

comment:6 Changed 4 years ago by andrew.mathas

Oh, I see that there are already documentation links, so feel free to ignore the above. This said, adding a link from the documentation in combinat/q_analogues.py to the code in this ticket would also be useful.

Last edited 4 years ago by andrew.mathas (previous) (diff)

comment:7 Changed 4 years ago by vbraun

  • Branch changed from public/quantum_groups/q_numbers-25067 to e0893e046355d1fd32a3d49fcce0a163d32ab354
  • Resolution set to fixed
  • Status changed from positive_review to closed
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