Allows a generalized Cartan matrix as input for Dynkin diagrams

[stumpc5]

Dynkin diagrams can currently not be constructed using a generalized Cartan matrix.

Apply: attachment: trac_12882-matrix_as_dynkin_diagram-ts.patch

Depends on #14137
Depends on #14516

CC: @sagetrac-sage-combinat

Component: combinatorics

Keywords: Weyl group, Dynkin diagram, Cartan matrix, days49

Author: Christian Stump, Travis Scrimshaw

Reviewer: Ben Salisbury

Merged: sage-5.12.beta4

Issue created by migration from https://trac.sagemath.org/ticket/12882

[stumpc5]

Description changed:

--- 
+++ 
@@ -1,3 +1,3 @@
 Dynkin diagrams can currently not be constructed using a generalized Cartan matrix.
 
-This patch implements this.
+This patch implements this. For the most recent version of the patch see the combinat queue!

[stumpc5]

Dependencies: #8327

[jdemeyer]

comment:3

Please fill in your real name as Author.

[stumpc5]

Author: Christian Stump

[hughrthomas]

comment:5

Hi Christian--

Your code is checking that all the off-diagonal entries in the input matrix are strictly negative. That seems a bit over-enthusiastic.

A doctest for the new functionality would also be good.

cheers,

Hugh

[hughrthomas]

comment:6

Hi Christian--

Why does this have #8327 listed as a dependency?

cheers,

Hugh

[stumpc5]

Changed dependencies from #8327 to none

[stumpc5]

comment:8

Replying to @hughrthomas:

Hi Christian--

Your code is checking that all the off-diagonal entries in the input matrix are strictly negative. That seems a bit over-enthusiastic.

A doctest for the new functionality would also be good.

Hi Hugh!

Thanks for bringing back my/our attention to this ticket!

I will be too busy to actively work on this patch in the next two weeks, but feel free to take it over and review/finish it if you like! I will now provide a version that you can work with (in particular, I deleted the dependency). Of course, you can as well wait until I finish the patch, if you prefer.

Best, Christian

[stumpc5]

Attachment: trac_12882-generalized_cartan_matrix_as_dynkin_diagram_input-cs.patch.gz