raise ValueError.new(msg)
# Check that all of the entries of ``A`` are nonnegative.
- if not all([ a >= 0 for a in A.list() ]):
+ if not all( a >= 0 for a in A.list() ):
return False
# It's nonnegative, so all we need to do is check that it's
# whenever we come across an index pair `$(i,j)$` with
# `$A_{ij} = 0$`.
spanning_set = []
- for j in range(0, A.ncols()):
- for i in range(0,j):
+ for j in xrange(A.ncols()):
+ for i in xrange(j):
if A[i,j] == 0:
M = A.matrix_space()
S = X.transpose() * (stdE(M,i,j) + stdE(M,j,i)) * X
# one of them is nonnegative, then return that.
A = random_psd(V, accept_zero, rank)
- while not all([ x >= 0 for x in A.list() ]):
+ while not all( x >= 0 for x in A.list() ):
A = random_psd(V, accept_zero, rank)
return A