Opened 12 years ago
Closed 12 years ago
#8984 closed enhancement (fixed)
Implementation of the Lenart--Postnikov alcove path crystal
Reported by: | brant.c.jones | Owned by: | sage-combinat |
---|---|---|---|
Priority: | major | Milestone: | sage-4.5.2 |
Component: | combinatorics | Keywords: | combinat, crystals |
Cc: | sage-combinat, brant@…, rlm | Merged in: | sage-4.5.2.alpha0 |
Authors: | Brant Jones | Reviewers: | Anne Schilling |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
This is an implementation of the Lenart--Postnikov alcove path model as described in:
A combinatorial model for crystals of Kac-Moody algebras. Trans. Amer. Math. Soc. 360 (2008).
It also implements to_coroot_lattice_morphism() and associated_coroot() in root_lattice_realization.py.
Depends on #8911 (trac_8911_categorification_crystals-as.patch).
Attachments (1)
Change History (20)
comment:1 Changed 12 years ago by
- Status changed from new to needs_review
comment:2 Changed 12 years ago by
- Description modified (diff)
comment:3 Changed 12 years ago by
comment:4 Changed 12 years ago by
- Cc brant@… added
comment:5 Changed 12 years ago by
- Keywords combinat crystals added
- Status changed from needs_review to needs_work
Thank you for implementing the alcove path model by Lenart and Postnikov. This will be a useful addition to sage.
It might be useful to add a few more words about the model you implemented
in the documentation of ClassicalCrystalOfAlcovePaths?. For example, you could
add that these are highest weight crystals for classical types
A_n
, B_n
, C_n
, D_n
and the exceptional types F_4
, G_2
, E_6
,
E_7
, E_8
.
Also, for the user it would be helpful to say how precisely one should enter the input data. For example, you could say
INPUT:
cartan_type
is the Cartan type of a classical Dynkin diagram
highest_weight
is a dominant weight as a list of coefficients of
the fundamental weights
Lambda_i
It might also be good to briefly describe how the crystal elements are represented so that the user can interpret the output.
Some technical comments:
(1) In combinat/crystals/alcove_path.py, it might be safer to only import the methods/classes that you really need for:
from sage.rings.integer import * (which appears twice, so please remove one!) from sage.misc.misc import * from sage.calculus.calculus import *
(2) All methods need EXAMPLES or TESTS. Please add them to the following methods in combinat/crystals/alcove_path.py for
classcall get_initial_chain fold compare_graphs
(3) Perhaps remove the commented out lines by # in
init list
(4) Add extra line after EXAMPLES:: get_chain_from_subset
(5) Remove the commented out weight
function
(6) You need TESTS or EXAMPLES to_coroot_lattice_morphism in sage/combinat/root_system/root_lattice_realization.py
Changed 12 years ago by
comment:6 Changed 12 years ago by
- Status changed from needs_work to needs_review
I have implemented all of the suggestions given by the reviewer above.
Please review the new version.
comment:7 Changed 12 years ago by
- Reviewers set to Anne Schilling
- Status changed from needs_review to positive_review
This patch implements the Lenart-Postnikov model for highest weight crystals for finite-dimensional Lie algebras. There are extensive tests to test that this gives the same crystal graph as other models.
All tests pass with sage-4.4.2 and the sage-combinat queue applied to this patch.
comment:8 Changed 12 years ago by
- Merged in set to sage-4.4.4.alpha1
- Resolution set to fixed
- Status changed from positive_review to closed
comment:9 Changed 12 years ago by
- Milestone set to sage-4.4.4
comment:10 Changed 12 years ago by
- Merged in sage-4.4.4.alpha1 deleted
- Resolution fixed deleted
- Status changed from closed to new
I had to backout this change from 4.4.4 for now. I was getting weird failures with random_element in matrix_group.py. I'm trying to figure out why this patch was causing it.
comment:11 Changed 12 years ago by
- Status changed from new to needs_review
comment:12 follow-up: ↓ 13 Changed 12 years ago by
- Status changed from needs_review to positive_review
comment:13 in reply to: ↑ 12 Changed 12 years ago by
Replying to mhansen:
Hi Mike,
What is the status on this now? Do you know why there were the strange failures in random_element in matrix_group.py?
Anne
comment:14 follow-up: ↓ 15 Changed 12 years ago by
See #9310
comment:15 in reply to: ↑ 14 Changed 12 years ago by
comment:16 Changed 12 years ago by
- Cc rlm added
Hi Robert!
Any chances to merge this patch, since it does not seem any more related to the failures than any other?
Thanks!
comment:17 Changed 12 years ago by
sage-4.5 is in feature freeze mode. Nothing but essential fixes will be merged until final release. I am strongly suggesting that the next release be patches to the sage library only (other than essential spkg fixes), and tickets like these deserve to go in then. (I would have had an alpha for such tickets in the 4.5 series, but the spkg issues are already holding things up long enough.)
comment:18 Changed 12 years ago by
- Merged in set to sage-4.5.2.alpha0
comment:19 Changed 12 years ago by
- Resolution set to fixed
- Status changed from positive_review to closed
Test whether Brant gets this message.