Random Boolean matrices have non-zero False elements

[szarnyasg]

I noticed that in the Triangle-Counting notebook, Cohen's algorithm returns 1929 while the Sandia variants return 1919. This is clearly a bug but the problem is not in the algorithms but in the data: the Matrix.from_random() method produces non-zero elements with False values. This can be demonstrated as follows:

M = Matrix.from_random(BOOL, 10, 10, 4, no_diagonal=True, make_symmetric=True, seed=42)
M.to_lists()

[[0, 1, 2, 3, 4, 4, 6, 9],
 [9, 4, 6, 4, 1, 3, 2, 0],
 [True, True, True, False, True, False, True, True]]

[michelp]

The Matrix.from_random method calls LAGraph_random() directly, so if you think this is a bug it might be best to file it there. As a workaround you could do Matrix.from_random(...).select(lib.GxB_NONZERO).

[szarnyasg]

from_random indeed behaves as it should. The triangle count is still strange though so I'm opening a followup issue.