def test_quaternion_inverse(self):
q0 = [1, 0, 0, 0]
q1 = quaternion_inverse(q0)
q = quaternion_multiply(q0, q1)
testing.assert_array_equal(q, [1, 0, 0, 0])
q0 = [1, 2, 3, 4]
q1 = quaternion_inverse(q0)
q = quaternion_multiply(q0, q1)
testing.assert_almost_equal(q, [1, 0, 0, 0])
def inverse(self):
"""Return inverse of this quaternion
Returns
-------
q : skrobot.coordinates.quaternion.Quaternion
new Quaternion class has inverse of this quaternion
Examples
--------
>>> from skrobot.coordinates.quaternion import Quaternion
>>> q = Quaternion()
>>> q
#<Quaternion 0x127e6da58 w: 1.0 x: 0.0 y: 0.0 z: 0.0>
>>> q.inverse
#<Quaternion 0x1281bbda0 w: 1.0 x: -0.0 y: -0.0 z: -0.0>
>>> q.q = [0, 1, 0, 0]
>>> q.inverse
#<Quaternion 0x1282b0cc0 w: 0.0 x: -1.0 y: -0.0 z: -0.0>
"""
return Quaternion(q=quaternion_inverse(self.q))