Opened 9 months ago

Closed 9 months ago

#15740 closed defect (fixed)

Better support for root systems which do not come from a Cartan type

Reported by: tscrim Owned by: sage-combinat
Priority: major Milestone: sage-6.2
Component: combinatorics Keywords: root systems
Cc: sage-combinat, nthiery Merged in:
Authors: Travis Scrimshaw Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: public/combinat/root_systems/non_typed-15740 (Commits) Commit: d52d5a57997ed7b79f1ef79afe2471a3f4c9dba9
Dependencies: Stopgaps:

Description (last modified by tscrim)

sage: d = DynkinDiagram()
sage: d.add_edge(1,2,3)
sage: d.add_edge(2,3)
sage: d.add_edge(3,4,3) 
sage: d.cartan_matrix()
[ 2 -1  0  0]
[-3  2 -1  0]
[ 0 -1  2 -1]
[ 0  0 -3  2]
sage: Q = d.root_system().root_lattice()
sage: Q
Root lattice of the Root system of type Dynkin diagram of rank 4
sage: al = Q.simple_roots()
sage: al[1].reflection(al[2]) # Boom

Change History (10)

comment:1 Changed 9 months ago by tscrim

  • Authors set to Travis Scrimshaw
  • Branch set to public/combinat/root_systems/non_typed-15740
  • Commit set to 1c0a6c7549966eb34e76931d7833a16dc5d36a4c
  • Description modified (diff)
  • Status changed from new to needs_review

I fixed this by giving a method symmetrizer to the Dynkin diagrams. This uncovered another small bug in that the index set wasn't being taking from the Dynkin diagram (i.e. its vertices) which is also fixed here.


New commits:

1c0a6c7Added symmetrizer method to Dynkin diagrams and fixed the index set for the corresp. Cartan matrix.

comment:2 Changed 9 months ago by chapoton

Looks good to me, but maybe one could add a test for the index_set correct behavior ?

comment:3 Changed 9 months ago by tscrim

It's implicitly there in the symmetrizer test, but I'll add an explicit test.

comment:4 Changed 9 months ago by git

  • Commit changed from 1c0a6c7549966eb34e76931d7833a16dc5d36a4c to 05415fc560664b5b8eb5af0e55a655c3974aacc2

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

ac731d2Trac 12141: finite algebras over fields
baa9c86Merge branch 'u/pbruin/12141-FiniteAlgebra' of trac.sagemath.org:sage into public/algebras/finite_algebra-12141
9052b7cPartial work on refactoring morphisms.
6badedbMerge branch 'public/combinat/root_systems/non_typed-15740' of trac.sagemath.org:sage into public/combinat/root_systems/non_typed-15740
05415fcAdded doctest to Cartan matrix.

comment:5 Changed 9 months ago by git

  • Commit changed from 05415fc560664b5b8eb5af0e55a655c3974aacc2 to d52d5a57997ed7b79f1ef79afe2471a3f4c9dba9

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

226d3e1Added symmetrizer method to Dynkin diagrams and fixed the index set for the corresp. Cartan matrix.
d52d5a5Added doctest to Cartan matrix.

comment:6 Changed 9 months ago by tscrim

After a little error with git (I forgot to base the branch off develop), I've added the requested doctest.

comment:7 Changed 9 months ago by chapoton

  • Keywords root systems added
  • Reviewers set to Frédéric Chapoton
  • Status changed from needs_review to positive_review

ok, good to go.

comment:8 Changed 9 months ago by tscrim

Thanks Frederic.

comment:9 Changed 9 months ago by vbraun_spam

  • Milestone changed from sage-6.1 to sage-6.2

comment:10 Changed 9 months ago by vbraun

  • Resolution set to fixed
  • Status changed from positive_review to closed
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