Feature #303
Rows and Columns of a matrix
Description
Two new fns rows(M) and cols(M) -- or should its name be columns?
These take a matrix and return a list of lists.
JAA notes that MakeMatByRows and MakeMatByCols take a "flattened" list of entries, so they are not quite inverses to rows and cols.
Related issues
History
#1
Updated by Anna Maria Bigatti about 11 years ago
Updated by I prefer cols (always the same abbreviation).
Or should it be GetCols?
Which name represents better it is making a copy?
- GetRow_long (indexed from 0)
- GetRow
- GetCol
- GetRows.
Update also these when making the new functions in CoCoALib.
#2
Updated by Anna Maria Bigatti over 9 years ago
- Target version set to CoCoALib-1.0
#3
Updated by John Abbott almost 5 years ago
Updated by - Category set to New Function
- Status changed from New to Resolved
- Assignee set to John Abbott
- Target version changed from CoCoALib-1.0 to CoCoALib-0.99700
- % Done changed from 0 to 70
I have just implemented GetRow, GetCol, GetRows and GetCols.
Perhaps the names are not ideal, but they are compatible with the names in CoCoA-5 (but indexes must be changed by 1).
I wonder whether a "flatten" function might be useful: read matrix elems row-by-row (or col-by-col) and put them into a std::vector<RingElem>. Anyway, I have not implemented this.
#4
Updated by John Abbott almost 5 years ago
- % Done changed from 70 to 80
I have now added GetRow, GetCol, GetRows and GetCols to MatrixOps.txt
Fixed a couple of minor bugs. Is it really worth writing a test?
(GetCol is effectively tested in anna.cocoa5)
#5
Updated by John Abbott over 4 years ago
- Status changed from Resolved to Closed
- % Done changed from 80 to 100
- Estimated time set to 1.66 h
Last comment was 8 months ago. The code is there (presumably added then); it is documented.
A comment says there are no tests, but that is probably not so important.
Closing.