Opened 8 years ago
Closed 7 years ago
#15215 closed task (duplicate)
Non-square matrices should inherit from ModuleElement, not RingElement
Reported by: | pbruin | Owned by: | |
---|---|---|---|
Priority: | minor | Milestone: | sage-duplicate/invalid/wontfix |
Component: | categories | Keywords: | inheritance |
Cc: | robertwb | Merged in: | |
Authors: | Reviewers: | Travis Scrimshaw | |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
Matrices inherit from RingElement
even if they are not square. Their parents do behave correctly.
sage: A = Matrix([[1, 2], [3, 4]]) sage: A.parent() in Rings() True sage: A.parent() in Modules(ZZ) True sage: isinstance(A, RingElement) True sage: B = Matrix([[1, 2, 3], [4, 5, 6]]) sage: B.parent() in Rings() False sage: A.parent() in Modules(ZZ) True sage: isinstance(B, RingElement) True
The same happens with Algebras(ZZ)
and AlgebraElement
.
Square matrices over a ring R
should be made to inherit dynamically from AlgebraElement
; non-square matrices should only inherit from ModuleElement
.
Motivation: Multiplication of matrices over a commutative ring R is in general only a bilinear map between R-modules (in general three different ones). Only if the matrices are square of the same size n can this be described as the multiplication map on an R-algebra, namely Mat_{n}(R).
This is a duplicate of #804.
Change History (4)
comment:1 Changed 8 years ago by
- Description modified (diff)
- Milestone changed from sage-5.13 to sage-duplicate/invalid/wontfix
comment:2 Changed 7 years ago by
- Status changed from new to needs_review
comment:3 Changed 7 years ago by
- Reviewers set to Travis Scrimshaw
- Status changed from needs_review to positive_review
comment:4 Changed 7 years ago by
- Resolution set to duplicate
- Status changed from positive_review to closed
I propose to close this as a duplicate of #804.