111 lines
3.5 KiB
Python
111 lines
3.5 KiB
Python
from typing import Callable, Optional, Tuple, TypeVar, Union, cast
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from ..backends import NumpyOps
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from ..config import registry
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from ..model import Model
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from ..types import Array3d, ArrayXd, ListXd, Padded, Ragged
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NUMPY_OPS = NumpyOps()
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ArrayTXd = TypeVar("ArrayTXd", bound=ArrayXd)
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SeqT = TypeVar("SeqT", bound=Union[Padded, Ragged, ListXd, ArrayXd])
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@registry.layers("with_array.v1")
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def with_array(layer: Model[ArrayTXd, ArrayTXd], pad: int = 0) -> Model[SeqT, SeqT]:
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"""Transform sequence data into a contiguous array on the way into and
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out of a model. Handles a variety of sequence types: lists, padded and ragged.
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If the input is an array, it is passed through unchanged.
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"""
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model: Model[SeqT, SeqT] = Model(
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f"with_array({layer.name})",
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forward,
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init=init,
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layers=[layer],
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attrs={"pad": pad},
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dims={name: layer.maybe_get_dim(name) for name in layer.dim_names},
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)
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return model
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def forward(
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model: Model[SeqT, SeqT], Xseq: SeqT, is_train: bool
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) -> Tuple[SeqT, Callable]:
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if isinstance(Xseq, Ragged):
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return cast(Tuple[SeqT, Callable], _ragged_forward(model, Xseq, is_train))
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elif isinstance(Xseq, Padded):
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return cast(Tuple[SeqT, Callable], _padded_forward(model, Xseq, is_train))
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elif not isinstance(Xseq, (list, tuple)):
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return model.layers[0](Xseq, is_train)
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else:
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return cast(Tuple[SeqT, Callable], _list_forward(model, Xseq, is_train))
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def init(
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model: Model[SeqT, SeqT], X: Optional[SeqT] = None, Y: Optional[SeqT] = None
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) -> None:
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layer: Model[ArrayXd, ArrayXd] = model.layers[0]
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layer.initialize(
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X=_get_array(model, X) if X is not None else X,
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Y=_get_array(model, Y) if Y is not None else Y,
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)
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for dim_name in layer.dim_names:
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value = layer.maybe_get_dim(dim_name)
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if value is not None:
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model.set_dim(dim_name, value)
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def _get_array(model, X: SeqT) -> ArrayXd:
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if isinstance(X, Ragged):
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return X.dataXd
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elif isinstance(X, Padded):
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return X.data
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elif not isinstance(X, (list, tuple)):
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return cast(ArrayXd, X)
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else:
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return model.ops.flatten(X)
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def _list_forward(
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model: Model[SeqT, SeqT], Xs: ListXd, is_train: bool
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) -> Tuple[ListXd, Callable]:
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layer: Model[ArrayXd, ArrayXd] = model.layers[0]
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pad = model.attrs["pad"]
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lengths = NUMPY_OPS.asarray1i([len(seq) for seq in Xs])
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Xf = layer.ops.flatten(Xs, pad=pad)
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Yf, get_dXf = layer(Xf, is_train)
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def backprop(dYs: ListXd) -> ListXd:
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dYf = layer.ops.flatten(dYs, pad=pad)
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dXf = get_dXf(dYf)
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return layer.ops.unflatten(dXf, lengths, pad=pad)
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return layer.ops.unflatten(Yf, lengths, pad=pad), backprop
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def _ragged_forward(
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model: Model[SeqT, SeqT], Xr: Ragged, is_train: bool
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) -> Tuple[Ragged, Callable]:
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layer: Model[ArrayXd, ArrayXd] = model.layers[0]
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Y, get_dX = layer(Xr.dataXd, is_train)
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def backprop(dYr: Ragged) -> Ragged:
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return Ragged(get_dX(dYr.dataXd), dYr.lengths)
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return Ragged(Y, Xr.lengths), backprop
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def _padded_forward(
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model: Model[SeqT, SeqT], Xp: Padded, is_train: bool
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) -> Tuple[Padded, Callable]:
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layer: Model[Array3d, Array3d] = model.layers[0]
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Y, get_dX = layer(Xp.data, is_train)
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def backprop(dYp: Padded) -> Padded:
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assert isinstance(dYp, Padded)
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dX = get_dX(dYp.data)
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return Padded(dX, dYp.size_at_t, dYp.lengths, dYp.indices)
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return Padded(Y, Xp.size_at_t, Xp.lengths, Xp.indices), backprop
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