Design #970
Weights in ElimMat?
Description
(similar for ElimHomogMat)
What should ElimMat([2,3], mat([[1,5,2]]));
return? (now it is (a))
(a) [0, 1, 1], [1, 5, 2], [0, 0, -1] (b) [0, 5, 2], [1, 5, 2], [0, 0, -1] (c) [0, 5, 2], [1, 0, 0], [0, 0, -1]
History
#1 Updated by John Abbott over 7 years ago
I prefer (c) to (b) perhaps because it is sparser.
(a) and (c) clearly do not give the same term-ordering though they are both clearly elimination orderings for indets 2 and 3.
What will you do if the weights are not given by a single row?
Case (a) clearly extends to any weights matrix; it is not so clear to me how to extend the other approach (just take first non-zero entry in the corresponding column?)
#2 Updated by John Abbott over 7 years ago
- Status changed from New to In Progress
- % Done changed from 0 to 10
I suggest proceeding with definition (a):
- it is already implemented
- it is easy to explain/describe
If we come across an application where definition (a) is inappropriate then we can consider an alternative definition inspired by that application.