is_pure

Quaternion.is_pure() → bool

Returns a bool value, where True if 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 – Boolean equal to True if \(q_w = 0\).

Return type:

bool

Examples

>>> q = Quaternion()
>>> q
Quaternion([1., 0., 0., 0.])
>>> q.is_pure()
False
>>> q = Quaternion([0., 1., 2., 3.])
>>> q
Quaternion([0.        , 0.26726124, 0.53452248, 0.80178373])
>>> q.is_pure()
True