fv_frame_reverse

t3toolbox.backend.fv_operations.fv_frame_reverse(frame)

def fv_frame_reverse(
        frame: typ.Tuple[
            typ.Sequence[NDArray],  # up_tucker_cores
            typ.Sequence[NDArray],  # down_tt_cores
            typ.Sequence[NDArray],  # left_tt_cores
            typ.Sequence[NDArray],  # right_tt_cores
        ],
) -> typ.Tuple[
    typ.Tuple[NDArray, ...],  # up_tucker_cores  (mode order reversed)
    typ.Tuple[NDArray, ...],  # down_tt_cores
    typ.Tuple[NDArray, ...],  # left_tt_cores    (= reversed old right cores)
    typ.Tuple[NDArray, ...],  # right_tt_cores   (= reversed old left cores)
]:

Reverse the mode order of a T3 frame 4-tuple (up, down, left, right).

The left and right TT families swap roles: reversing a left-orthogonal chain yields a right-orthogonal one, so the new left family is the reversed old right family and vice versa (the up-tucker family is reversed; the down family is reversed per tt_reverse()). The redundant left/right store makes this exact with no re-orthogonalization. Inverse of itself.

Parameters:

frame (t3toolbox.backend.common.typ.Tuple[t3toolbox.backend.common.typ.Sequence[NDArray], t3toolbox.backend.common.typ.Sequence[NDArray], t3toolbox.backend.common.typ.Sequence[NDArray], t3toolbox.backend.common.typ.Sequence[NDArray]])

Return type:

t3toolbox.backend.common.typ.Tuple[t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis], t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis], t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis], t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis]]