def test_FFLDU():
A = DenseMatrix(3, 3, [1, 2, 3, 5, -3, 2, 6, 2, 1])
L, D, U = A.FFLDU()
assert L == DenseMatrix(3, 3, [1, 0, 0, 5, -13, 0, 6, -10, 1])
assert D == DenseMatrix(3, 3, [1, 0, 0, 0, -13, 0, 0, 0, -13])
assert U == DenseMatrix(3, 3, [1, 2, 3, 0, -13, -13, 0, 0, 91])
