Ticket #12667 (closed defect: fixed)
category root lattice realization issue: infinite loop while trying to reflect to the positive chamber
|Reported by:||mshimo||Owned by:||sage-combinat|
|Report Upstream:||N/A||Reviewers:||Anne Schilling|
|Authors:||Mark Shimozono||Merged in:||sage-5.0.beta11|
Description (last modified by jdemeyer) (diff)
version 5.0 beta7
sage/combinat/root_system/root_lattice_realizations.py element methods to_positive_chamber, reduced_word may give infinite loops for affine root systems
R=sage.combinat.root_system.all.RootSystem(['A',1,1]) rl = R.root_lattice() mu = rl.from_vector(vector([0,1])) mu.to_positive_chamber()
For elements of a root lattice realization:
- Added method reflect which reflects across a hyperplane orthogonal
to a (co)root.
- Renamed to_positive_chamber to to_dominant_chamber, and added case checking
for affine root systems which prevents infinite looping. Root systems that are not finite and not affine are not checked.
- Added method weyl_action which acts on a vector by a Weyl group element.
- Added method weyl_stabilizer which returns indices of simple reflections
fixing a weight.
- Cc sage-combinat added
- Reviewers set to Anne Schilling
comment:10 in reply to: ↑ 9 Changed 15 months ago by aschilling
- Status changed from new to needs_review
- Description modified (diff)