code: def from_rotation_vector(rot):
      
      rot = np.array(rot, copy=False)
      quats = np.zeros(rot.shape[:-1]+(4,))
      quats[..., 1:] = rot[...]/2
      quats = as_quat_array(quats)
      return np.exp(quats)
docs: Convert input 3-vector in axis-angle representation to unit quaternion
  
      Parameters
      ----------
      rot: (Nx3) float array
          Each vector represents the axis of the rotation, with norm
          proportional to the angle of the rotation in radians.
  
      Returns
      -------
      q: array of quaternions
          Unit quaternions resulting in rotations corresponding to input
          rotations.  Output shape is rot.shape[:-1].