def test_mat_partition():
N = 100
A = poisson_1d(N)
A_sub = partition_mat_by_num(A, 10)
A_block = [[A_sub[i, j] for j in xrange(10)] for i in xrange(10)]
A_reconstructed_from_block = sparse.bmat(A_block).tocsr()
assert (A - A_reconstructed_from_block).nnz == 0
def test_poisson_1d():
N = 10
A = poisson_1d(N)
assert np.sum(A.data) == 0.0
