from typing import Optional, List
from thinc.types import Floats2d
from thinc.api import Model, reduce_mean, Linear, list2ragged, Logistic
from thinc.api import chain, concatenate, clone, Dropout, ParametricAttention
from thinc.api import SparseLinear, Softmax, softmax_activation, Maxout, reduce_sum
from thinc.api import HashEmbed, with_array, with_cpu, uniqued
from thinc.api import Relu, residual, expand_window
from thinc.layers.chain import init as init_chain
from ...attrs import ID, ORTH, PREFIX, SUFFIX, SHAPE, LOWER
from ...util import registry
from ..extract_ngrams import extract_ngrams
from ..staticvectors import StaticVectors
from ..featureextractor import FeatureExtractor
from ...tokens import Doc
from .tok2vec import get_tok2vec_width
@registry.architectures.register("spacy.TextCatCNN.v1")
def build_simple_cnn_text_classifier(
tok2vec: Model, exclusive_classes: bool, nO: Optional[int] = None
) -> Model[List[Doc], Floats2d]:
"""
Build a simple CNN text classifier, given a token-to-vector model as inputs.
If exclusive_classes=True, a softmax non-linearity is applied, so that the
outputs sum to 1. If exclusive_classes=False, a logistic non-linearity
is applied instead, so that outputs are in the range [0, 1].
"""
with Model.define_operators({">>": chain}):
cnn = tok2vec >> list2ragged() >> reduce_mean()
if exclusive_classes:
output_layer = Softmax(nO=nO, nI=tok2vec.maybe_get_dim("nO"))
model = cnn >> output_layer
model.set_ref("output_layer", output_layer)
else:
linear_layer = Linear(nO=nO, nI=tok2vec.maybe_get_dim("nO"))
model = cnn >> linear_layer >> Logistic()
model.set_ref("output_layer", linear_layer)
model.set_ref("tok2vec", tok2vec)
model.set_dim("nO", nO)
model.attrs["multi_label"] = not exclusive_classes
return model
@registry.architectures.register("spacy.TextCatBOW.v1")
def build_bow_text_classifier(
exclusive_classes: bool,
ngram_size: int,
no_output_layer: bool,
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
with Model.define_operators({">>": chain}):
sparse_linear = SparseLinear(nO)
model = extract_ngrams(ngram_size, attr=ORTH) >> sparse_linear
model = with_cpu(model, model.ops)
if not no_output_layer:
output_layer = softmax_activation() if exclusive_classes else Logistic()
model = model >> with_cpu(output_layer, output_layer.ops)
model.set_ref("output_layer", sparse_linear)
model.attrs["multi_label"] = not exclusive_classes
return model
@registry.architectures.register("spacy.TextCatEnsemble.v2")
def build_text_classifier_v2(
tok2vec: Model[List[Doc], List[Floats2d]],
linear_model: Model[List[Doc], Floats2d],
nO: Optional[int] = None,
) -> Model[List[Doc], Floats2d]:
exclusive_classes = not linear_model.attrs["multi_label"]
with Model.define_operators({">>": chain, "|": concatenate}):
width = tok2vec.maybe_get_dim("nO")
attention_layer = ParametricAttention(
width
) # TODO: benchmark performance difference of this layer
maxout_layer = Maxout(nO=width, nI=width)
linear_layer = Linear(nO=nO, nI=width)
cnn_model = (
tok2vec
>> list2ragged()
>> attention_layer
>> reduce_sum()
>> residual(maxout_layer)
>> linear_layer
>> Dropout(0.0)
)
nO_double = nO * 2 if nO else None
if exclusive_classes:
output_layer = Softmax(nO=nO, nI=nO_double)
else:
output_layer = Linear(nO=nO, nI=nO_double) >> Dropout(0.0) >> Logistic()
model = (linear_model | cnn_model) >> output_layer
model.set_ref("tok2vec", tok2vec)
if model.has_dim("nO") is not False:
model.set_dim("nO", nO)
model.set_ref("output_layer", linear_model.get_ref("output_layer"))
model.set_ref("attention_layer", attention_layer)
model.set_ref("maxout_layer", maxout_layer)
model.set_ref("linear_layer", linear_layer)
model.attrs["multi_label"] = not exclusive_classes
model.init = init_ensemble_textcat
return model
def init_ensemble_textcat(model, X, Y) -> Model:
tok2vec_width = get_tok2vec_width(model)
model.get_ref("attention_layer").set_dim("nO", tok2vec_width)
model.get_ref("maxout_layer").set_dim("nO", tok2vec_width)
model.get_ref("maxout_layer").set_dim("nI", tok2vec_width)
model.get_ref("linear_layer").set_dim("nI", tok2vec_width)
init_chain(model, X, Y)
return model
# TODO: move to legacy
@registry.architectures.register("spacy.TextCatEnsemble.v1")
def build_text_classifier_v1(
width: int,
embed_size: int,
pretrained_vectors: Optional[bool],
exclusive_classes: bool,
ngram_size: int,
window_size: int,
conv_depth: int,
dropout: Optional[float],
nO: Optional[int] = None,
) -> Model:
# Don't document this yet, I'm not sure it's right.
cols = [ORTH, LOWER, PREFIX, SUFFIX, SHAPE, ID]
with Model.define_operators({">>": chain, "|": concatenate, "**": clone}):
lower = HashEmbed(
nO=width, nV=embed_size, column=cols.index(LOWER), dropout=dropout, seed=10
)
prefix = HashEmbed(
nO=width // 2,
nV=embed_size,
column=cols.index(PREFIX),
dropout=dropout,
seed=11,
)
suffix = HashEmbed(
nO=width // 2,
nV=embed_size,
column=cols.index(SUFFIX),
dropout=dropout,
seed=12,
)
shape = HashEmbed(
nO=width // 2,
nV=embed_size,
column=cols.index(SHAPE),
dropout=dropout,
seed=13,
)
width_nI = sum(layer.get_dim("nO") for layer in [lower, prefix, suffix, shape])
trained_vectors = FeatureExtractor(cols) >> with_array(
uniqued(
(lower | prefix | suffix | shape)
>> Maxout(nO=width, nI=width_nI, normalize=True),
column=cols.index(ORTH),
)
)
if pretrained_vectors:
static_vectors = StaticVectors(width)
vector_layer = trained_vectors | static_vectors
vectors_width = width * 2
else:
vector_layer = trained_vectors
vectors_width = width
tok2vec = vector_layer >> with_array(
Maxout(width, vectors_width, normalize=True)
>> residual(
(
expand_window(window_size=window_size)
>> Maxout(
nO=width, nI=width * ((window_size * 2) + 1), normalize=True
)
)
)
** conv_depth,
pad=conv_depth,
)
cnn_model = (
tok2vec
>> list2ragged()
>> ParametricAttention(width)
>> reduce_sum()
>> residual(Maxout(nO=width, nI=width))
>> Linear(nO=nO, nI=width)
>> Dropout(0.0)
)
linear_model = build_bow_text_classifier(
nO=nO,
ngram_size=ngram_size,
exclusive_classes=exclusive_classes,
no_output_layer=False,
)
nO_double = nO * 2 if nO else None
if exclusive_classes:
output_layer = Softmax(nO=nO, nI=nO_double)
else:
output_layer = Linear(nO=nO, nI=nO_double) >> Dropout(0.0) >> Logistic()
model = (linear_model | cnn_model) >> output_layer
model.set_ref("tok2vec", tok2vec)
if model.has_dim("nO") is not False:
model.set_dim("nO", nO)
model.set_ref("output_layer", linear_model.get_ref("output_layer"))
model.attrs["multi_label"] = not exclusive_classes
return model
@registry.architectures.register("spacy.TextCatLowData.v1")
def build_text_classifier_lowdata(
width: int, dropout: Optional[float], nO: Optional[int] = None
) -> Model[List[Doc], Floats2d]:
# Don't document this yet, I'm not sure it's right.
# Note, before v.3, this was the default if setting "low_data" and "pretrained_dims"
with Model.define_operators({">>": chain, "**": clone}):
model = (
StaticVectors(width)
>> list2ragged()
>> ParametricAttention(width)
>> reduce_sum()
>> residual(Relu(width, width)) ** 2
>> Linear(nO, width)
)
if dropout:
model = model >> Dropout(dropout)
model = model >> Logistic()
return model