UT3FrameWeights.from_ut3weights
===============================

.. py:method:: t3toolbox.uniform_frame_variations_format.UT3FrameWeights.from_ut3weights(weights)
   :classmethod:


   .. code-block:: python

      def from_ut3weights(cls, weights: 'ut3.UT3Weights') -> 'UT3FrameWeights':


   Build a tangent metric from uniform base-point edge weights (e.g.
   ``UT3Weights.from_ut3svd(x)``): ``up = down = tucker``, ``left = tt[:-1]``, ``right = tt[1:]``, on
   the supercores **and** the masks. The TT slicing follows the ``H_i`` bond convention (``H_i``'s
   left bond is TT bond ``i``, its right bond is bond ``i+1``) -- simple but convention-dependent,
   hence a named method.

   The result pairs with a **minimal-rank** tangent (where the complement rank ``nD`` equals the
   Tucker rank ``nU``, as for ``ut3svd`` output); a non-minimal tangent has ``nD < nU`` and is
   rejected by :py:meth:`is_consistent_with` rather than silently absorbed. The Grasedyck-Kramer
   metric is ``UT3FrameWeights.from_ut3weights(UT3Weights.from_ut3svd(x)).reciprocal()``.