def test_to_rotation_matrix_results_in_close_rotation():
angle = 0.5 * np.pi
axis = np.array([[1, 0, 0]]).T
R = SO3.Exp(angle * axis).matrix
# Invalidate a valid rotation matrix by scaling it.
R_scaled = 3 * R
# Fit to SO(3).
R_closest = SO3.to_so3_matrix(R_scaled)
# Result should be the same rotation matrix.
np.testing.assert_almost_equal(R_closest, R, 14)
# Perturb the rotation matrix with random noise.
R_noisy = R + 0.01 * np.random.rand(3, 3)
# Fit to SO(3)
so3_closest = SO3(R_noisy)
# Extract angle-axis representation.
angle_closest, axis_closest = so3_closest.Log(True)
# Result should be close to the same rotation.
np.testing.assert_almost_equal(angle_closest, angle, 2)
np.testing.assert_almost_equal(axis_closest, axis, 2)
def test_to_rotation_matrix_results_in_valid_rotation():
A = np.random.rand(3, 3)
R = SO3.to_so3_matrix(A)
np.testing.assert_almost_equal(R @ R.T, np.identity(3), 14)
np.testing.assert_almost_equal(np.linalg.det(R), 1, 14)