utv_entries_derivatives
=======================

.. py:function:: t3toolbox.backend.utv_sampling.utv_entries_derivatives(index, pp, frame_data, variations_data, order)

   .. code-block:: python

      def utv_entries_derivatives(
              index,            # int array, shape=(d,)+W -- the multi-indices
              pp,               # perturbation vectors P, len=d, ith elm_shape=W+(Ni,)
              frame_data,       # UT3Frame .data
              variations_data,  # UT3Variations .data
              order,            # highest derivative order
      ):  # -> scalar jets, shape=(order+1,)+W+K+C


   Symmetric entry derivatives of a uniform tangent vector at ``index`` (the bare ``𝒥``; fiber slicing,
   so only ``pp`` is packed).