spaCy/spacy/ml/extract_spans.py
kadarakos 0de1f8bf73 Spancat speed improvement (#12577)
* avoid nesting then flattening

* mypy fix

* Apply suggestions from code review

* Add type for indices

* Run full matrix for mypy

* Add back modified type: ignore

* Revert "Run full matrix for mypy"

This reverts commit e218873d04.

---------

Co-authored-by: Adriane Boyd <adrianeboyd@gmail.com>
2023-05-12 09:55:22 +02:00

67 lines
2.2 KiB
Python

from typing import List, Tuple, Callable
from thinc.api import Model, to_numpy
from thinc.types import Ragged, Ints1d
from ..util import registry
@registry.layers("spacy.extract_spans.v1")
def extract_spans() -> Model[Tuple[Ragged, Ragged], Ragged]:
"""Extract spans from a sequence of source arrays, as specified by an array
of (start, end) indices. The output is a ragged array of the
extracted spans.
"""
return Model(
"extract_spans", forward, layers=[], refs={}, attrs={}, dims={}, init=init
)
def init(model, X=None, Y=None):
pass
def forward(
model: Model, source_spans: Tuple[Ragged, Ragged], is_train: bool
) -> Tuple[Ragged, Callable]:
"""Get subsequences from source vectors."""
ops = model.ops
X, spans = source_spans
assert spans.dataXd.ndim == 2
indices = _get_span_indices(ops, spans, X.lengths)
if len(indices) > 0:
Y = Ragged(X.dataXd[indices], spans.dataXd[:, 1] - spans.dataXd[:, 0]) # type: ignore[arg-type, index]
else:
Y = Ragged(
ops.xp.zeros(X.dataXd.shape, dtype=X.dataXd.dtype),
ops.xp.zeros((len(X.lengths),), dtype="i"),
)
x_shape = X.dataXd.shape
x_lengths = X.lengths
def backprop_windows(dY: Ragged) -> Tuple[Ragged, Ragged]:
dX = Ragged(ops.alloc2f(*x_shape), x_lengths)
ops.scatter_add(dX.dataXd, indices, dY.dataXd) # type: ignore[arg-type]
return (dX, spans)
return Y, backprop_windows
def _get_span_indices(ops, spans: Ragged, lengths: Ints1d) -> Ints1d:
"""Construct a flat array that has the indices we want to extract from the
source data. For instance, if we want the spans (5, 9), (8, 10) the
indices will be [5, 6, 7, 8, 8, 9].
"""
spans, lengths = _ensure_cpu(spans, lengths)
indices: List[int] = []
offset = 0
for i, length in enumerate(lengths):
spans_i = spans[i].dataXd + offset
for j in range(spans_i.shape[0]):
indices.extend(range(spans_i[j, 0], spans_i[j, 1])) # type: ignore[arg-type, call-overload]
offset += length
return ops.asarray1i(indices)
def _ensure_cpu(spans: Ragged, lengths: Ints1d) -> Tuple[Ragged, Ints1d]:
return Ragged(to_numpy(spans.dataXd), to_numpy(spans.lengths)), to_numpy(lengths)