pytransform3d.transformations
.norm_exponential_coordinates¶
- pytransform3d.transformations.norm_exponential_coordinates(Stheta)[source]¶
Normalize exponential coordinates of transformation.
- Parameters
- Sthetaarray-like, shape (6,)
Exponential coordinates of transformation: S * theta = (omega_1, omega_2, omega_3, v_1, v_2, v_3) * theta, where the first 3 components are related to rotation and the last 3 components are related to translation. Theta is the rotation angle and h * theta the translation. Theta should be >= 0. Negative rotations will be represented by a negative screw axis instead. This is relevant if you want to recover theta from exponential coordinates.
- Returns
- Sthetaarray, shape (6,)
Normalized exponential coordinates of transformation with theta in [0, pi]. Note that in the case of pure translation no normalization is required because the representation is unique. In the case of rotation by pi, there is an ambiguity that will be resolved so that the screw pitch is positive.