t3_segment
==========

.. py:function:: t3toolbox.backend.t3_operations.t3_segment(data, start = None, stop = None)

   .. code-block:: python

      def t3_segment(
              data: typ.Tuple[
                  typ.Sequence[NDArray],  # tucker_cores. len=d
                  typ.Sequence[NDArray],  # tt_cores.     len=d
              ],
              start: typ.Optional[int] = None,  # Python slice start (None -> 0; negatives wrap)
              stop:  typ.Optional[int] = None,  # Python slice stop  (None -> d; negatives wrap)
      ) -> typ.Tuple[
          typ.Tuple[NDArray, ...],  # tucker_cores[start:stop]
          typ.Tuple[NDArray, ...],  # tt_cores[start:stop]
      ]:


   Contiguous mode-segment of a T3: slice both core families over modes ``start:stop``.

   ``start``/``stop`` follow Python slice semantics (``None`` -> the ends; negatives wrap), with a
   length >= 1 guard. Inverse of :py:func:`t3_concatenate`.