Opened 8 years ago

Closed 8 years ago

#18590 closed enhancement (fixed)

coxeter sorting words

Reported by: Vincent Pilaud Owned by:
Priority: major Milestone: sage-6.8
Component: combinatorics Keywords: Sage Days 64.5
Cc: Christian Stump, Viviane Pons Merged in:
Authors: Vincent Pilaud Reviewers: Viviane Pons, Christian Stump
Report Upstream: N/A Work issues:
Branch: 6b47229 (Commits, GitHub, GitLab) Commit: 6b47229c032f62e73bf2429304c1118b3618f834
Dependencies: Stopgaps:

Status badges

Description (last modified by Vincent Pilaud)

Coxeter sorting is used to define sortable elements of a Coxeter group.

New methods are:

  • rank of the Coxeter group
  • support of an element (the simple reflections that appear in the reduced expressions of the element)
  • has_full_support tells if the support contains all simple reflections
  • coxeter_sorting_word returns the c-sorting word of an element
  • is_coxeter_sortable tells if an element is c-sortable

Change History (12)

comment:1 Changed 8 years ago by Vincent Pilaud

Branch: u/vpilaud/coxeter_sorting_words

comment:2 Changed 8 years ago by Vincent Pilaud

Cc: Christian Stump added
Commit: deea7d9a79758f87cb2a87390e7eb5387d2c6112
Component: PLEASE CHANGEcombinatorics
Description: modified (diff)
Keywords: Sage Days 64.5 added
Type: PLEASE CHANGEenhancement

New commits:

deea7d9add support for sorting words

comment:3 Changed 8 years ago by git

Commit: deea7d9a79758f87cb2a87390e7eb5387d2c611240cf52b378a65230514a0b2192f26ccf58ea712a

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

40cf52badd rank function and documentation on coxeter sorting words in coxeter_groups

comment:4 Changed 8 years ago by Vincent Pilaud

Status: newneeds_review

comment:5 Changed 8 years ago by git

Commit: 40cf52b378a65230514a0b2192f26ccf58ea712ad1d24a608ff799549a357239614623baf00dc47a

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

d1d24a6fix bug documentation

comment:6 Changed 8 years ago by Viviane Pons

Authors: Vincent Pilaud
Branch: u/vpilaud/coxeter_sorting_wordsu/VivianePons/coxeter_sorting_words
Cc: Viviane Pons added
Commit: d1d24a608ff799549a357239614623baf00dc47ad1db90cb346dfafac5f6e512ecdb956862828aef
Reviewers: Viviane Pons
Status: needs_reviewneeds_work

I did some small formating fixes, and I found this error:

sage: W = CoxeterGroup(["A",3])
sage: c = W.from_reduced_word([1,2,3])
sage: l = [w for w in W if w.is_coxeter_sortable(c)]
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-3-ab902ac679a2> in <module>()
----> 1 l = [w for w in W if w.is_coxeter_sortable(c)]

/home/viviane/sage/local/lib/python2.7/site-packages/sage/categories/coxeter_groups.pyc in is_coxeter_sortable(self, c, sorting_word)
   2064                         return False
   2065                 else:
-> 2066                     containment_list[s] = False
   2067                 i += 1
   2068                 if i == n:

IndexError: list assignment index out of range

Also, please update the ticket description to give more details


New commits:

d1d24a6fix bug documentation
d1db90cSome small doc formating fix

comment:7 Changed 8 years ago by Vincent Pilaud

Branch: u/VivianePons/coxeter_sorting_wordsu/vpilaud/coxeter_sorting_words

comment:8 Changed 8 years ago by Vincent Pilaud

Commit: d1db90cb346dfafac5f6e512ecdb956862828aef70315c85d0360b02eff867f1b0f840fb582ed957
Description: modified (diff)
Status: needs_workneeds_review

New commits:

70315c8fix bug is_sortable_element

comment:9 Changed 8 years ago by Viviane Pons

Branch: u/vpilaud/coxeter_sorting_wordsu/VivianePons/coxeter_sorting_words
Commit: 70315c85d0360b02eff867f1b0f840fb582ed9576b47229c032f62e73bf2429304c1118b3618f834

I've made a few small format fix. I'm happy with the ticket. Christian, if you're happy too you can put it to positive review.


New commits:

6b47229Small formating fixes (adding outputs, fixing doc indent)

comment:10 Changed 8 years ago by Christian Stump

Reviewers: Viviane PonsViviane Pons, Christian Stump

looks good!

comment:11 Changed 8 years ago by Christian Stump

Status: needs_reviewpositive_review

comment:12 Changed 8 years ago by Volker Braun

Branch: u/VivianePons/coxeter_sorting_words6b47229c032f62e73bf2429304c1118b3618f834
Resolution: fixed
Status: positive_reviewclosed
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