check_perturbation_vectors
==========================

.. py:function:: t3toolbox.backend.sampling_derivatives.check_perturbation_vectors(ww, pp)

   .. code-block:: python

      def check_perturbation_vectors(
              ww: typ.Sequence[NDArray],  # points X,       len=d, elm_shape=W+(Ni,)
              pp: typ.Sequence[NDArray],  # perturbation P, len=d, elm_shape=W+(Ni,)
      ) -> None:


   Structural check (hard error): the perturbation ``P`` (``pp``) shares the sample stack ``W`` and
   mode dims of the points ``X`` (``ww``) -- each sample pairs a point with a direction. Used by the
   derivative-probe/apply frontends; shapes are static, so this is jit-safe.