Is there a way or hack to operate with matrices with negative indices? For example a 3x3 matrix with row indices {-1,0,1} and column indices {-1, 0, 1}. So one can do m[-1,-1] for first row and column entry, while still retain matrix operations (ring ops, determinant, etc.). I'm dealing with random walks where the symetry needs that.
Python uses negative indices to index from the end.
So for a 3 by 3 matrix, you can think of the indices as 0, 1, 2 or equivalently -3, -2, -1.
In other words you could also think of them as 0, 1, -1.
sage: m = matrix(3, [1 .. 9])
sage: m
[1 2 3]
[4 5 6]
[7 8 9]
sage: m[-1, -1]
9
sage: m[-1, 1]
8
sage: m[1, -1]
6ok thanks for chiming in fast, but I'd welcome a more direct representation if there's one. The python convention seems to obscure my reasoning about matrices.
Asked: 2 years ago
Seen: 352 times
Last updated: Jul 25 '22
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