def test_negation(self):
"""Test that we can negate a vector"""
a1 = tuples.Tuple(["a", "b", "c", "d"], 1, -2, 3, -4)
a2 = -a1
self.assertEqual(a2, tuples.Tuple(["a", "b", "c", "d"], -1, 2, -3, 4))
def test_scalar_division(self):
"""Test that we can divide a tuple by a scalar"""
a1 = tuples.Tuple(["a", "b", "c", "d"], 1, -2, 3, -4)
a2 = a1 / 2
self.assertEqual(a2,
tuples.Tuple(["a", "b", "c", "d"], 0.5, -1, 1.5, -2))
def test_scalar_multiplication(self):
"""Test that we can multiple a vector by a scalar"""
a1 = tuples.Tuple(["a", "b", "c", "d"], 1, -2, 3, -4)
a2 = a1 * 3.5
a3 = a1 * 0.5
self.assertEqual(
a2, tuples.Tuple(["a", "b", "c", "d"], 3.5, -7, 10.5, -14))
self.assertEqual(a3,
tuples.Tuple(["a", "b", "c", "d"], 0.5, -1, 1.5, -2))
def test_matrix_tuple_multiplication(self):
"""Test that we can multiple a matrix by a tuple"""
M = matrices.Matrix(4, 4)
M.set_row(0, [1, 2, 3, 4])
M.set_row(1, [2, 4, 4, 2])
M.set_row(2, [8, 6, 4, 1])
M.set_row(3, [0, 0, 0, 1])
t = tuples.Tuple(["x", "y", "z", "w"], 1, 2, 3, 1)
t2 = M * t
self.assertEqual(t2, tuples.Tuple(["x", "y", "z", "w"], 18, 24, 33, 1))
def __mul__(self, other):
"""Perform matrix multiplication"""
if isinstance(other, Matrix):
if self.rows != other.rows or self.columns != other.columns:
raise exceptions.IncompatibleLengthError
M = Matrix(self.rows, self.columns)
for i in range(self.rows):
for j in range(self.columns):
my_row = self.get_row(i)
other_column = other.get_col(j)
M.set(i, j,
sum([x * y for x, y in zip(my_row, other_column)]))
return M
if isinstance(other, tuples.Tuple):
zeros = [0] * len(other.fillables)
r = tuples.Tuple(other.fillables, *zeros)
for i in range(self.rows):
my_row = self.get_row(i)
result = sum([
my_row[j] * other.values()[j] for j in range(self.columns)
])
setattr(r, other.fillables[i], result)
return r
# If we get down here it wasn't any type we can multiply with
raise ValueError
def test_point__tuple(self):
"""Test that we can initialize and read from a point as a tuple"""
p = tuples.Tuple(["x", "y", "z", "w"], 4.3, -4.2, 3.1, 1)
self.assertEqual(p.x, 4.3)
self.assertEqual(p.y, -4.2)
self.assertEqual(p.z, 3.1)
self.assertEqual(p.w, 1)
def test_vector__tuple(self):
"""Test that we can initialize and read from a vector as a tuple"""
v = tuples.Tuple(["x", "y", "z", "w"], 4.3, -4.2, 3.1, 0)
self.assertEqual(v.x, 4.3)
self.assertEqual(v.y, -4.2)
self.assertEqual(v.z, 3.1)
self.assertEqual(v.w, 0)
def test_addition(self):
"""test that we can add a vector to a point"""
a1 = points.Point(3, -2, 5)
a2 = vectors.Vector(-2, 3, 1)
a3 = a1 + a2
self.assertEqual(a3, tuples.Tuple(["x", "y", "z", "w"], 1, 1, 6, 1))
self.assertEqual(a3, points.Point(1, 1, 6))
def test_identity_matrix_mult(self):
"""Test we can identify the identity matrix by a matrix and tuple"""
ident = transforms.Identity(3)
M = matrices.Matrix(3, 3)
M.set_row(0, [1, 2, 3])
M.set_row(1, [3, 2, 1])
M.set_row(2, [2, 4, 6])
M2 = M * ident
self.assertEqual(M2, M)
t = tuples.Tuple(["a", "b", "c"], 1, 2, 3)
t2 = ident * t
self.assertEqual(t2, t)