def test_matrix(self):
assert Quaternion().matrix == Matrix.identity(4)
def test_dot_product_neutral_element(self):
a = Matrix((2, 2), range(4))
b = Matrix.identity(2)
assert a @ b == a
assert a @ b == b @ a
def test_dot_product_inverse(self):
a = Matrix((2, 2), (4, 3, 2, 1))
b = Matrix((2, 2), (-0.5, 1.5, 1, -2))
assert a @ b == Matrix.identity(2)
assert b @ a == Matrix.identity(2)
def test_identity(self):
assert Matrix.identity(4) == Matrix((4, 4))
assert Matrix.identity(4) == Matrix(
(4, 4), (1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1))
