Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

Sage Reference Manual: Matrices and Spaces of Matrices, Release 6.1.1
•indices - whether or not to return the indices and elements of this matrix that satisfy the function.
OUTPUT: If indices is not specified, return a matrix with 1 where f is satisfied and 0 where it is not.
If indices is specified, return a dictionary containing the elements of this matrix satisfying f.
EXAMPLES:
sage: M = matrix(4,3,[1, -1/2, -1, 1, -1, -1/2, -1, 0, 0, 2, 0, 1])
sage: M.find(lambda entry:entry==0)
[0 0 0]
[0 0 0]
[0 1 1]
[0 1 0]
sage: M.find(lambda u:u1.2)
[0 0 0]
[0 0 0]
[0 0 0]
[1 0 0]
sage: sorted(M.find(lambda u:u!=0,indices=True).keys()) == M.nonzero_positions()
True
get_subdivisions()
Returns the current subdivision of self.
EXAMPLES:
sage: M = matrix(5, 5, range(25))
sage: M.subdivisions()
([], [])
sage: M.subdivide(2,3)
sage: M.subdivisions()
([2], [3])
sage: N = M.parent()(1)
sage: N.subdivide(M.subdivisions()); N
[1 0 0|0 0]
[0 1 0|0 0]
[-----+---]
[0 0 1|0 0]
[0 0 0|1 0]
[0 0 0|0 1]
gram_schmidt(orthonormal=False)
173