Opened 9 years ago

Closed 9 years ago

#15740 closed defect (fixed)

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

Reported by: Travis Scrimshaw Owned by: Sage Combinat CC user
Priority: major Milestone: sage-6.2
Component: combinatorics Keywords: root systems
Cc: Sage Combinat CC user, Nicolas M. Thiéry Merged in:
Authors: Travis Scrimshaw Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: public/combinat/root_systems/non_typed-15740 (Commits, GitHub, GitLab) Commit: d52d5a57997ed7b79f1ef79afe2471a3f4c9dba9
Dependencies: Stopgaps:

Status badges

Description (last modified by Travis Scrimshaw)

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 years ago by Travis Scrimshaw

Authors: Travis Scrimshaw
Branch: public/combinat/root_systems/non_typed-15740
Commit: 1c0a6c7549966eb34e76931d7833a16dc5d36a4c
Description: modified (diff)
Status: newneeds_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 years ago by Frédéric Chapoton

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

comment:3 Changed 9 years ago by Travis Scrimshaw

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

comment:4 Changed 9 years ago by git

Commit: 1c0a6c7549966eb34e76931d7833a16dc5d36a4c05415fc560664b5b8eb5af0e55a655c3974aacc2

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 years ago by git

Commit: 05415fc560664b5b8eb5af0e55a655c3974aacc2d52d5a57997ed7b79f1ef79afe2471a3f4c9dba9

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 years ago by Travis Scrimshaw

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

comment:7 Changed 9 years ago by Frédéric Chapoton

Keywords: root systems added
Reviewers: Frédéric Chapoton
Status: needs_reviewpositive_review

ok, good to go.

comment:8 Changed 9 years ago by Travis Scrimshaw

Thanks Frederic.

comment:9 Changed 9 years ago by For batch modifications

Milestone: sage-6.1sage-6.2

comment:10 Changed 9 years ago by Volker Braun

Resolution: fixed
Status: positive_reviewclosed
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