def translation_matrix(dx=0, dy=0, dz=0):
""" Return matrix for translation along vector (dx, dy, dz). """
return np.array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[dx, dy, dz, 1]])
def rotate_z_matrix(radians):
""" Return matrix for rotating about the z-axis by 'radians' radians """
c = np.cos(radians)
s = np.sin(radians)
return np.array([[c, -s, 0, 0],
[s, c, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]])
def identity_matrix():
return np.array([[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]])