ut3_rank_adjustment_sweep
=========================

.. py:function:: t3toolbox.backend.ut3_svd.ut3_rank_adjustment_sweep(data, direction = 'right_to_left')

   .. code-block:: python

      def ut3_rank_adjustment_sweep(
              data: UT3Data,
              direction: str = 'right_to_left',  # 'right_to_left' | 'left_to_right'
      ) -> UT3Data:


   A single lossless directional sweep that drops structurally-redundant ranks -- the uniform analog
   of ragged ``rank_adjustment_sweep`` (the minimization step; :py:func:`ut3svd` does not minimize).

   ``'right_to_left'`` returns a **right-orthogonal** result; ``'left_to_right'`` a **left-orthogonal**
   one. It reaches the minimal ranks **only if the input is already orthogonal in the opposite
   direction** -- a :py:func:`ut3svd` result is left-orthogonal, so ``'right_to_left'`` minimizes it.
   (The precondition is required here: unlike ragged, the static masks shrink to the minimal ranks, so a
   wrong-direction call on a non-oppositely-orthogonal input is lossy. Compose both directions for a
   minimal result in a chosen gauge.)