is_pure

ahrs.common.quaternion.QuaternionArray.is_pure(self) → ndarray

Returns an array of boolean values, where a value is True if its corresponding quaternion is pure.

A pure quaternion has a scalar part equal to zero: \(\mathbf{q} = 0 + xi + yj + zk\)

\[\begin{split}\left\{ \begin{array}{ll} \mathrm{True} & \: w = 0 \\ \mathrm{False} & \: \mathrm{otherwise} \end{array} \right.\end{split}\]

Returns:

out – Array of booleans.

Return type:

np.ndarray

Example

>>> Q = QuaternionArray(np.random.random((3, 4))-0.5)
>>> Q[1, 0] = 0.0
>>> Q.view()
QuaternionArray([[ 0.32014817,  0.47060011,  0.78255824,  0.25227621],
                 [ 0.        , -0.79009137,  0.47021242, -0.26103598],
                 [-0.65182559, -0.3032904 ,  0.16078433, -0.67622979]])
>>> Q.is_pure()
array([False,  True, False])