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Design #1279

Tidy up code for matrix determinant

Added by John Abbott almost 5 years ago. Updated over 3 years ago.

Status:
Closed
Priority:
Normal
Assignee:
John Abbott
Category:
Tidying
Target version:
CoCoALib-0.99800
Start date:
03 May 2019
Due date:
% Done:

100%

Estimated time:
2.66 h
Spent time:
2.60 h

Description

I recently encountered an unexpected error while trying to compute the determinant of a 2x2 matrix over ZZ/(841) where 841 = 29^2.

There seem to be several "suboptimal" aspects in the code:
  • DetDirect has an incorrect assertion that the ring is a PolyRing
  • DetDirect probably should not have been called anyway
  • why wasn't det2x2 called?

Review the code, and tidy it up!

Related issues

Related to CoCoALib - Bug #1280: Determinant & Inverse of matrix over non integral domainIn Progress2019-05-03

History

#1 Updated by John Abbott almost 5 years ago

  • Related to Bug #1280: Determinant & Inverse of matrix over non integral domain added

#2 Updated by John Abbott over 4 years ago

  • Target version changed from CoCoALib-0.99700 to CoCoALib-0.99800

#3 Updated by John Abbott over 3 years ago

  • Status changed from New to Resolved
  • Assignee set to John Abbott
  • % Done changed from 0 to 70

Main dispatch fn is ConstMatrixViewBase::myDet around matrix.C:221

The code has already been considerably cleaned up, but still performs poorly for some inputs.

#4 Updated by John Abbott over 3 years ago

  • Description updated (diff)
  • Status changed from Resolved to Closed
  • % Done changed from 70 to 100
  • Estimated time set to 2.66 h

The current version is acceptable; it could be made better, but there are plenty of other more important issues (at the moment).

Closing.

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