Feature #1209
New function: HasPositiveGrading
Description
It would be handy to have a function saying whether a polynomial ring (or a ppmonoid) has a positive grading.
This would make it cleaner to check than getting the submatrix of the order matrix, with the given grading dim....
Then use it to check Hilbert input!!!!
Related issues
History
#1
Updated by Anna Maria Bigatti over 5 years ago
Updated by - Related to Bug #1211: HilbertSeries should check grading added
#2
Updated by John Abbott over 4 years ago
Updated by - Description updated (diff)
Do you simply mean a GradingDim function which can be applied to a PPMonoid or a SparsePolyRing?
#3
Updated by Anna Maria Bigatti over 4 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 30
Now I understand what I meant.
+ There is a function called IsPositiveGrading taking a weight matrix for input. This means that we have to create the weight matrix (as the submatrix of the ordering matrix) in order to call it.
+ In CoCoALib we do not create memory with submat, but in CoCoA we do. So we just need a CoCoALib shortcut to IsPositiveMatrix(submat(..)).
#4
Updated by Anna Maria Bigatti over 4 years ago
- Related to Design #825: IsPositiveGrading -- really need 2 signatures? added
#5
Updated by Anna Maria Bigatti over 4 years ago
Apparently we decided to remove the function I was going to use (IsPosiveGrading with two args), but in the time being we had implemented all the necessary ingredients (GradingMat using LongRange), so the function is just a one-liner.
I implemented it for SparsePolyRing. Should I also make it for PPMonoid?
#6
Updated by Anna Maria Bigatti over 4 years ago
- % Done changed from 30 to 50
We decided (personal discussion) to implement it only for ring, because the real utility of this function is for cocoa-5.
In cocoalib we can easily and equivalently call IsPositiveGrading(GradingMat(PPM)) instead.
#7
Updated by Anna Maria Bigatti over 4 years ago
- Subject changed from New functions: HasPositiveGrading to New function: HasPositiveGrading
- Status changed from In Progress to Closed
- % Done changed from 50 to 100
Done. Tested from CoCoA-5 (false for #1211, true in anna.cocoa5).