Opened 8 years ago
Closed 7 years ago
#14095 closed defect (fixed)
SymmetricGroup as a proper WeylGroup
Reported by:  nthiery  Owned by:  sagecombinat 

Priority:  major  Milestone:  sage6.2 
Component:  combinatorics  Keywords:  days45, coxeter 
Cc:  tscrim  Merged in:  
Authors:  Frédéric Chapoton  Reviewers:  Travis Scrimshaw 
Report Upstream:  N/A  Work issues:  
Branch:  b790a37 (Commits, GitHub, GitLab)  Commit:  b790a3788bfeda6e2f685fbf3be5b01d21dd9680 
Dependencies:  Stopgaps: 
Description
During Sara Billey's talk, it came up that not all of the Weyl group functionalities are available for the symmetric group:
 The symmetric group does not implement CartanType?
 The Stanley symmetric function code uses the old fashionned W.unit() rather than W.one(). There might be some other occurences that should be cleaned up
Test case:
sage: G = SymmetricGroup(4) sage: w = G.from_reduced_word([3,2,3,1]) sage: w.stanley_symmetric_function() 3*m[1, 1, 1, 1] + 2*m[2, 1, 1] + m[2, 2] + m[3, 1]
Change History (14)
comment:1 Changed 8 years ago by
 Milestone changed from sage5.11 to sage5.12
comment:2 Changed 7 years ago by
 Cc tscrim added
comment:3 Changed 7 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:4 Changed 7 years ago by
 Branch set to u/chapoton/14095
 Commit set to c97072a455237563dea59c12bfb071dc9b355b7e
 Keywords coxeter added
 Status changed from new to needs_review
comment:5 Changed 7 years ago by
FYI  On my TODO list to review.
comment:6 Changed 7 years ago by
 Branch changed from u/chapoton/14095 to u/tscrim/14095
 Commit changed from c97072a455237563dea59c12bfb071dc9b355b7e to 3f77996aca99c269302db147dc4826cc51e8a5bf
 Reviewers set to Travis Scrimshaw
Looks good overall. I've caught one more unit
in the category AffineWeylGroups
. I've also marked some tests as # long time
in permgroup_named.py
since basic testing of that file was taking forever. Plus I've done some other tweaks to that file (gawd that file needs cleanup though). So if you're happy with my changes then positive review.
New commits:
4df5a62  One more unit() to one().

3f77996  Some misc cleanup to permgroup_named.py.

comment:7 Changed 7 years ago by
Looks good to me. But maybe one should add the "test case" in the ticket description somewhere ?
comment:8 Changed 7 years ago by
 Branch changed from u/tscrim/14095 to u/chapoton/14095
 Commit changed from 3f77996aca99c269302db147dc4826cc51e8a5bf to 849583956d1fc8e111a7a1d977d79f772872a179
I have added a doctest and taken the opportunity to correct the reference section. I agree with your previous changes. If you agree with mines, please set to positive review.
New commits:
8495839  trac #14095 added the new example from the trac ticket

comment:9 Changed 7 years ago by
 Commit changed from 849583956d1fc8e111a7a1d977d79f772872a179 to 5f088582bc60c9030acc766009d2092d37c44089
Branch pushed to git repo; I updated commit sha1. New commits:
5f08858  correct formatting of doc and raise syntax for python3

comment:10 Changed 7 years ago by
 Commit changed from 5f088582bc60c9030acc766009d2092d37c44089 to 1573f6b7e5577a4e60a54f7afd85aa5c09ea5cad
Branch pushed to git repo; I updated commit sha1. New commits:
1573f6b  more doc correction

comment:11 Changed 7 years ago by
Could you also change that \dots
into \cdots
? With that, you can set positive review on my behalf. Thanks Frederic.
comment:12 Changed 7 years ago by
 Commit changed from 1573f6b7e5577a4e60a54f7afd85aa5c09ea5cad to b790a3788bfeda6e2f685fbf3be5b01d21dd9680
Branch pushed to git repo; I updated commit sha1. New commits:
b790a37  trac #14095 cdots instead of dots

comment:14 Changed 7 years ago by
 Branch changed from u/chapoton/14095 to b790a3788bfeda6e2f685fbf3be5b01d21dd9680
 Resolution set to fixed
 Status changed from positive_review to closed
Here is a git branch that
1) introduces the
cartan_type
method inSymmetricGroup
2) transforms a few
W.unit()
intoW.one()
New commits:
trac #14095 remove use of .unit ; added cartan_type for SymmetricGroup