Opened 8 years ago

Closed 7 years ago

Last modified 7 years ago

#8811 closed enhancement (fixed)

Translation for elements of a root lattice and related features and fixes

Reported by: aschilling Owned by: sage-combinat
Priority: major Milestone: sage-4.4.4
Component: combinatorics Keywords: root systems, affine weyl groups, translations
Cc: sage-combinat Merged in: sage-4.4.4.alpha0
Authors: Nicolas M. Thiéry Reviewers: Anne Schilling
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description (last modified by nthiery)

This patch implements translation for elements of a root lattice and related features and fixes::

  • New method translation for elements of a root lattice
  • New methods reduced_word_of_alcove_morphism, dynkin_diagram_automorphism_of_alcove_morphism, reduced_word_of_translation, _test_reduced_word_of_translation
  • Added extensive TESTS to compare with Kashiwara's private notes
  • Fixed dynkin diagram for type BC
  • Fixed CartanType?.translation_factors to implement its specification correctly in affine type BC. Imported the full test suite from MuPAD-Combinat. Also fixes and tests for proper typing of the coefficients (ZZ/QQ).
  • Bug fix in WeylGroup?: the matrices were defined over QQ instead of the base ring of the underlying root lattice realization.

Attachments (1)

trac_8811_reduced_word_of_translations-nt.patch (44.7 KB) - added by nthiery 7 years ago.

Download all attachments as: .zip

Change History (8)

comment:1 Changed 8 years ago by nthiery

  • Description modified (diff)
  • Keywords root systems affine weyl groups translations added
  • Milestone set to sage-4.4.3
  • Reviewers set to Anne Schilling, ...
  • Status changed from new to needs_work

comment:2 Changed 7 years ago by nthiery

  • Description modified (diff)
  • Status changed from needs_work to needs_review

comment:3 Changed 7 years ago by nthiery

  • Description modified (diff)

comment:4 Changed 7 years ago by nthiery

  • Description modified (diff)
  • Summary changed from Translation for elements of a root lattice to Translation for elements of a root lattice and related features and fixes

comment:5 Changed 7 years ago by aschilling

  • Reviewers changed from Anne Schilling, ... to Anne Schilling
  • Status changed from needs_review to positive_review

I carefully checked the results of translation_factor, adding extra tests to compare with Kashiwara's private notes. Nicolas and I discussed at length the correct factors for type BC (see the corresponding doc in the code).

All tests passed on massena and all tests in combinat/root_systems passed on my machine.

Positive review.

comment:6 Changed 7 years ago by mhansen

  • Merged in set to sage-4.4.4.alpha0
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:7 Changed 7 years ago by mhansen

  • Authors changed from Nicolas M. Thiery to Nicolas M. Thiéry
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