Opened 2 years ago

Closed 2 years ago

#22789 closed enhancement (fixed)

Jacobians of transition maps

Reported by: egourgoulhon Owned by: mmancini
Priority: major Milestone: sage-8.0
Component: geometry Keywords: manifold, transition_map, Jacobian
Cc: Merged in:
Authors: Eric Gourgoulhon Reviewers: Marco Mancini
Report Upstream: N/A Work issues:
Branch: 3c3c725 (Commits) Commit: 3c3c7257bfd6a66a053184d8f074c96c01f2eb8b
Dependencies: Stopgaps:

Description

New methods jacobian and jacobian_det are implemented in the class DiffCoordChange managing transition maps on differentiable manifolds; they return respectively the Jacobian matrix and the Jacobian determinant of the transition map. Besides, the Jacobian determinant is no longer computed at each creation of a transition map, but only on demand. The computational method itself, implemented in MultiCoordFunction.jacobian_det, has been improved. It relies now on the standard determinant of matrices and no longer on the cofactor method. The latter was implemented as a workaround to a bug in symbolic charpoly (fixed in #14403) but had a serious performance issue in high dimensions (n > 4), as reported ​here.

Change History (5)

comment:1 Changed 2 years ago by egourgoulhon

  • Branch set to public/manifolds/jacobian-22789
  • Commit set to 3c3c7257bfd6a66a053184d8f074c96c01f2eb8b
  • Status changed from new to needs_review

New commits:

​3c3c725Add methods jacobian() and jacobian_det() to class DiffCoordChange

comment:2 Changed 2 years ago by mmancini

  • Owner changed from (none) to mmancini

comment:3 Changed 2 years ago by mmancini

  • Status changed from needs_review to positive_review

comment:4 Changed 2 years ago by mmancini

  • Reviewers set to Marco Mancini

comment:5 Changed 2 years ago by vbraun

  • Branch changed from public/manifolds/jacobian-22789 to 3c3c7257bfd6a66a053184d8f074c96c01f2eb8b
  • Resolution set to fixed
  • Status changed from positive_review to closed
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