is_identity

Quaternion.is_identity() → bool

Returns a bool value, where True if quaternion is identity quaternion.

An identity quaternion has its scalar part equal to 1, and its vector part equal to 0, such that \(\mathbf{q} = 1 + 0i + 0j + 0k\).

\[\begin{split}\left\{ \begin{array}{ll} \mathrm{True} & \: \mathbf{q}\ = \begin{pmatrix} 1 & 0 & 0 & 0 \end{pmatrix} \\ \mathrm{False} & \: \mathrm{otherwise} \end{array} \right.\end{split}\]

Returns:

out – Boolean equal to True if \(\mathbf{q}=\begin{pmatrix}1 & 0 & 0 & 0\end{pmatrix}\).

Return type:

bool

Examples

>>> q = Quaternion()
>>> q
Quaternion([1., 0., 0., 0.])
>>> q.is_identity()
True
>>> q = Quaternion([0., 1., 0., 0.])
>>> q
Quaternion([0., 1., 0., 0.])
>>> q.is_identity()
False