pack_sample
===========

.. py:function:: t3toolbox.backend.uniform_fitting.pack_sample(name, sample, N)

   .. code-block:: python

      def pack_sample(name, sample, N):


   Pack the loop-invariant mode-vectors of ``sample`` once (mirror-tolerant: packed input is kept).

   A boundary helper (the uniform kinds run on packed vectors of width ``N``): dispatches
   :py:func:`~t3toolbox.backend.ut3_operations.pack_if_ragged` per sampling-kind (``ww`` for apply/probe,
   both ``ww``/``pp`` for the derivative kinds; the integer ``index`` is never packed). Used by
   :py:func:`uniform_least_squares_problem` and the frontend :py:mod:`t3toolbox.fitting` uniform models.