Opened 6 years ago
Closed 6 years ago
#21159 closed defect (fixed)
Cached generator matrices and parity check matrices should be immutable
Reported by:  jsrn  Owned by:  

Priority:  major  Milestone:  sage7.6 
Component:  coding theory  Keywords:  linear code, beginner, rd3 
Cc:  dlucas  Merged in:  
Authors:  Clément Pernet  Reviewers:  David Lucas 
Report Upstream:  N/A  Work issues:  
Branch:  ac0e4f9 (Commits, GitHub, GitLab)  Commit:  ac0e4f91f1f964492d6c8732d3d1de80593d59da 
Dependencies:  #21328  Stopgaps: 
Description (last modified by )
In all linear code classes, constructed generator matrices and parity check matrices are cached for efficiency. However, they are often not immutable, leading to incorrect behaviour if the user inadvertently changes them.
sage: C = codes.GeneralizedReedSolomonCode(GF(7).list(), 3) sage: C.generator_matrix()[0,0] = 0 sage: C.generator_matrix().row(0) in C False
All such cached matrices should be made immutable by G.set_immutable(True)
.
Change History (12)
comment:1 Changed 6 years ago by
 Description modified (diff)
comment:2 Changed 6 years ago by
 Branch set to u/cpernet/immutable_generator_matrix
comment:3 Changed 6 years ago by
 Commit set to d07341b9e50608753929ef79dd538cc73823f358
 Component changed from PLEASE CHANGE to coding theory
 Milestone changed from sage7.3 to sage7.6
 Status changed from new to needs_review
comment:4 Changed 6 years ago by
 Status changed from needs_review to needs_work
comment:5 Changed 6 years ago by
 Commit changed from d07341b9e50608753929ef79dd538cc73823f358 to 84090767d241f9e6cd9c5f0df779b05ce746ac64
Branch pushed to git repo; I updated commit sha1. New commits:
8409076  fix mistake: make the matrix immutable, not the tuple

comment:6 Changed 6 years ago by
 Status changed from needs_work to needs_review
comment:7 Changed 6 years ago by
 Keywords rd3 added
 Reviewers set to David Lucas
 Status changed from needs_review to positive_review
Tests pass and doc builds, I agree with your changes, setting to positive review.
David
comment:8 Changed 6 years ago by
 Branch changed from u/cpernet/immutable_generator_matrix to u/dlucas/immutable_generator_matrix
comment:9 Changed 6 years ago by
 Commit changed from 84090767d241f9e6cd9c5f0df779b05ce746ac64 to ac0e4f91f1f964492d6c8732d3d1de80593d59da
 Status changed from positive_review to needs_review
Well, reopenig this ticket to include parity check codes (#21328) in it. Waiting for review...
David
New commits:
b77de0f  Added new file that introduces the new paritycheck code class. Initializes code class, generator matrix encoder class, straightforward encoder class and minimum distance method.

0b0d2f8  Correcting mistakes. Two errors are still waiting for correction: ParityCheckCodeStraightforwardEncoder.unencode_nocheck and ParityCheckCodeGeneratorMatrixEncoder.__init__

62abcd7  Fixed merge conflict.

1aa4b4e  Fixed doctests. Shorter output. Generator matrix encoder inherits from the generic one. Fixed encoders. Cleaned the code.

64ee227  Merged ticket #21328 in

ac0e4f9  Immutable generator matrix for parity codes

comment:10 Changed 6 years ago by
 Dependencies set to #21328
comment:11 Changed 6 years ago by
 Status changed from needs_review to positive_review
Positive review to the merge and last commit by dlucas.
comment:12 Changed 6 years ago by
 Branch changed from u/dlucas/immutable_generator_matrix to ac0e4f91f1f964492d6c8732d3d1de80593d59da
 Resolution set to fixed
 Status changed from positive_review to closed
I processed all code classes with the following update:
@cached_method
decorator when it was missing to agenerator_matrix
or aparity_check
methodBranch attached ready for review.