Opened 9 years ago
Closed 7 years ago
#13248 closed enhancement (fixed)
Coxeter groups: all elements of length N, random elements
Reported by: | sdenton | Owned by: | joyner |
---|---|---|---|
Priority: | minor | Milestone: | sage-6.3 |
Component: | group theory | Keywords: | sd40, coxeter |
Cc: | nthiery, heglin, tscrim, darij | Merged in: | |
Authors: | Tom Denton, Frédéric Chapoton | Reviewers: | Mike Zabrocki, Travis Scrimshaw |
Report Upstream: | N/A | Work issues: | |
Branch: | a96be6f (Commits) | Commit: | a96be6f6bbe8a90d811570c5023620955e82cce7 |
Dependencies: | Stopgaps: |
Description (last modified by )
Two commonly desired constructions in a Coxeter group are to: a) Iterate over all elements of a given length - this happens especially in affine or other infinite coxeter groups in order to test hypotheses, construct homogenous elements, etc... b) Choose a random element, possibly with length specified. This often occurs to see if a non-special element has a given property.
Iterating over all elements of a given length in particular has a nice solution (due to N. Thiery) and anecdotally has been implemented (usually in an inelegant fashion) by numerous community members in response to short-term problems.
We provide some code implementing these functions!
Change History (18)
comment:1 Changed 9 years ago by
- Keywords sd40 added
comment:2 Changed 7 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:3 Changed 7 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:4 Changed 7 years ago by
- Keywords coxeter added
comment:5 Changed 7 years ago by
That's strange; I'm not sure why it isn't there.
The code should be the same used in the AffinePermutationGroup
for the methods elements_of_length
and random_element
.
Example:
sage: A=AffinePermutationGroup?(['A',4,1])
sage: len(list(A.elements_of_length(1)))
5
sage: A.random_element(4)
Type A affine permutation with window [0, 4, 3, 2, 6]
comment:6 Changed 7 years ago by
Maybe we should then move the code to Coxeter groups, it it works.
comment:7 Changed 7 years ago by
- Branch set to u/chapoton/13248
- Commit set to c2ce1c2aadf83f0e4e10ec2ac307286ac5ecbd1f
here is a git branch, moving elements_of_length into the category of coxeter groups
New commits:
c2ce1c2 | trac #13248 first step : moving elements_of_length to coxeter groups
|
comment:8 Changed 7 years ago by
- Commit changed from c2ce1c2aadf83f0e4e10ec2ac307286ac5ecbd1f to 93faac6d489a6b3a54ff5573e90444290bcced8c
Branch pushed to git repo; I updated commit sha1. New commits:
93faac6 | Merge branch 'u/chapoton/13248' of trac.sagemath.org:sage into 13248
|
comment:9 Changed 7 years ago by
- Cc nthiery added; ntiery removed
comment:10 Changed 7 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:11 Changed 7 years ago by
- Description modified (diff)
- Status changed from new to needs_review
- Work issues set to random not yet done
comment:12 Changed 7 years ago by
- Commit changed from 93faac6d489a6b3a54ff5573e90444290bcced8c to a94f96885688a39006c58fceb041694a2716b372
comment:13 Changed 7 years ago by
- Commit changed from a94f96885688a39006c58fceb041694a2716b372 to fb613e237c7fb1785256f33fe115d7890c6120bb
Branch pushed to git repo; I updated commit sha1. New commits:
fb613e2 | trac #13248 remove code duplication
|
comment:14 Changed 7 years ago by
- Work issues random not yet done deleted
comment:15 Changed 7 years ago by
- Cc tscrim darij added
- Reviewers changed from zabrocki to Mike Zabrocki
ping ?
comment:16 Changed 7 years ago by
- Branch changed from u/chapoton/13248 to u/tscrim/13248
- Commit changed from fb613e237c7fb1785256f33fe115d7890c6120bb to 707c9c39ec02ba112f19e614a26c99e430b7bd67
- Reviewers changed from Mike Zabrocki to Mike Zabrocki, Travis Scrimshaw
Hey Frederic,
I've done some minor tweaks and made it so that random_element
chooses the length at random in [0, 1000]
(so the word is not too long) if not specified. LGTM otherwise, so if you're happy with my changes, then positive review.
New commits:
ec5652c | Merge branch 'u/chapoton/13248' of trac.sagemath.org:sage into u/tscrim/13248
|
707c9c3 | Some review tweaks.
|
comment:17 Changed 7 years ago by
- Branch changed from u/tscrim/13248 to u/chapoton/13248
- Commit changed from 707c9c39ec02ba112f19e614a26c99e430b7bd67 to a96be6f6bbe8a90d811570c5023620955e82cce7
- Status changed from needs_review to positive_review
Hello, and thanks.
I just corrected a typo in "chosen".
I'm setting this to positive review.
New commits:
a96be6f | trac #13248 just corrected a typo in "chosen"
|
comment:18 Changed 7 years ago by
- Branch changed from u/chapoton/13248 to a96be6f6bbe8a90d811570c5023620955e82cce7
- Resolution set to fixed
- Status changed from positive_review to closed
Where is the code ?