def test_boomerang_mobility_spd(self):
''' Test that the mobility is SPD for random configuration. '''
theta = np.random.normal(0., 1., 4)
theta = Quaternion(theta / np.linalg.norm(theta))
location = [np.random.uniform(2.5, 4.) for _ in range(3)]
mobility = bmr.boomerang_mobility([location], [theta])
def is_pos_def(x):
return np.all(np.linalg.eigvals(x) > 0)
self.assertTrue(is_pos_def(mobility))
for j in range(6):
for k in range(j + 1, 6):
self.assertAlmostEqual(mobility[j][k], mobility[k][j])
def test_change_mobility_origin(self):
''' This tests the function in utils.py that transforms a mobility
about one point to a mobility about another.
'''
# Random location and orientation
location = [[0., 0., np.random.uniform(4., 7.)]]
orientation = np.random.normal(0., 1., 4)
orientation = [Quaternion(orientation / np.linalg.norm(orientation))]
mobility = bmr.boomerang_mobility(location, orientation)
# Choose a random other point, evaluate mobility.
point = location[0] + np.random.normal(0., 1., 3)
mobility_2 = bmr.boomerang_mobility_at_arbitrary_point(
location, orientation, point)
# Transfer mobility to point using util function.
transferred_mobility_2 = transfer_mobility(mobility, location[0],
point)
# Compare results.
for j in range(0, 6):
for k in range(0, 6):
self.assertAlmostEqual(mobility_2[j, k],
transferred_mobility_2[j, k])