t3variations_to_ut3variations#

t3toolbox.backend.ufv_conversions.t3variations_to_ut3variations(variations_data, N=None, nU=None, nD=None, rL=None, rR=None)#
def t3variations_to_ut3variations(
        variations_data: typ.Tuple[
            typ.Tuple[NDArray, ...],  # tucker_variations, len=d, elm_shape=C+(nDi, Ni)
            typ.Tuple[NDArray, ...],  # tt_variations,     len=d, elm_shape=C+(rLi, nUi, rR(i+1))
        ],
        N:  typ.Optional[int] = None,   # padded mode dim   (default max(shape))
        nU: typ.Optional[int] = None,   # padded up rank    (default max(up_ranks))
        nD: typ.Optional[int] = None,   # padded down rank  (default max(down_ranks))
        rL: typ.Optional[int] = None,   # padded left rank  (default max(left_ranks))
        rR: typ.Optional[int] = None,   # padded right rank (default max(right_ranks))
) -> typ.Tuple[
    NDArray,                          # tucker_variations supercore, (d,)+C+(nD, N)
    NDArray,                          # tt_variations supercore,     (d,)+C+(rL, nU, rR)
    typ.Tuple[int, ...],              # shape
    typ.Tuple[NDArray, NDArray, NDArray, NDArray],  # (variations up, down, left, right) masks, all (d,)-leading
]:

Pack a ragged T3Variations core-tuple into uniform variation .data.

Inverse of ut3variations_to_t3variations(). The variation masks are all (d,)-leading (a variation occupies one TT slot, not a boundary edge), so the left/right ranks are the per-slot bonds rLi / rR(i+1) – NOT a (d+1,) edge sequence. ufv_make_frame_masks builds the prefix masks from whatever leading shape its rank args carry, so it serves here too.

Parameters:

  • variations_data (t3toolbox.backend.common.typ.Tuple[t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis], t3toolbox.backend.common.typ.Tuple[NDArray, Ellipsis]])

  • N (t3toolbox.backend.common.typ.Optional[int])

  • nU (t3toolbox.backend.common.typ.Optional[int])

  • nD (t3toolbox.backend.common.typ.Optional[int])

  • rL (t3toolbox.backend.common.typ.Optional[int])

  • rR (t3toolbox.backend.common.typ.Optional[int])

Return type:

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