spaCy/spacy/_ml.py
2017-07-25 18:57:59 +02:00

411 lines
12 KiB
Python

import ujson
from thinc.api import add, layerize, chain, clone, concatenate, with_flatten
from thinc.neural import Model, Maxout, Softmax, Affine
from thinc.neural._classes.hash_embed import HashEmbed
from thinc.neural.ops import NumpyOps, CupyOps
from thinc.neural.util import get_array_module
import random
from thinc.neural._classes.convolution import ExtractWindow
from thinc.neural._classes.static_vectors import StaticVectors
from thinc.neural._classes.batchnorm import BatchNorm
from thinc.neural._classes.resnet import Residual
from thinc.neural import ReLu
from thinc.neural._classes.selu import SELU
from thinc import describe
from thinc.describe import Dimension, Synapses, Biases, Gradient
from thinc.neural._classes.affine import _set_dimensions_if_needed
from thinc.api import FeatureExtracter, with_getitem
from thinc.neural.pooling import Pooling, max_pool, mean_pool, sum_pool
from thinc.neural._classes.attention import ParametricAttention
from thinc.linear.linear import LinearModel
from thinc.api import uniqued, wrap
from .attrs import ID, ORTH, LOWER, NORM, PREFIX, SUFFIX, SHAPE, TAG, DEP
from .tokens.doc import Doc
import numpy
import io
@layerize
def _flatten_add_lengths(seqs, pad=0, drop=0.):
ops = Model.ops
lengths = ops.asarray([len(seq) for seq in seqs], dtype='i')
def finish_update(d_X, sgd=None):
return ops.unflatten(d_X, lengths, pad=pad)
X = ops.flatten(seqs, pad=pad)
return (X, lengths), finish_update
@layerize
def _logistic(X, drop=0.):
xp = get_array_module(X)
if not isinstance(X, xp.ndarray):
X = xp.asarray(X)
# Clip to range (-10, 10)
X = xp.minimum(X, 10., X)
X = xp.maximum(X, -10., X)
Y = 1. / (1. + xp.exp(-X))
def logistic_bwd(dY, sgd=None):
dX = dY * (Y * (1-Y))
return dX
return Y, logistic_bwd
def _zero_init(model):
def _zero_init_impl(self, X, y):
self.W.fill(0)
model.on_data_hooks.append(_zero_init_impl)
if model.W is not None:
model.W.fill(0.)
return model
@layerize
def _preprocess_doc(docs, drop=0.):
keys = [doc.to_array([LOWER]) for doc in docs]
keys = [a[:, 0] for a in keys]
ops = Model.ops
lengths = ops.asarray([arr.shape[0] for arr in keys])
keys = ops.xp.concatenate(keys)
vals = ops.allocate(keys.shape[0]) + 1
return (keys, vals, lengths), None
def _init_for_precomputed(W, ops):
if (W**2).sum() != 0.:
return
reshaped = W.reshape((W.shape[1], W.shape[0] * W.shape[2]))
ops.xavier_uniform_init(reshaped)
W[:] = reshaped.reshape(W.shape)
@describe.on_data(_set_dimensions_if_needed)
@describe.attributes(
nI=Dimension("Input size"),
nF=Dimension("Number of features"),
nO=Dimension("Output size"),
W=Synapses("Weights matrix",
lambda obj: (obj.nF, obj.nO, obj.nI),
lambda W, ops: _init_for_precomputed(W, ops)),
b=Biases("Bias vector",
lambda obj: (obj.nO,)),
d_W=Gradient("W"),
d_b=Gradient("b")
)
class PrecomputableAffine(Model):
def __init__(self, nO=None, nI=None, nF=None, **kwargs):
Model.__init__(self, **kwargs)
self.nO = nO
self.nI = nI
self.nF = nF
def begin_update(self, X, drop=0.):
# X: (b, i)
# Yf: (b, f, i)
# dY: (b, o)
# dYf: (b, f, o)
#Yf = numpy.einsum('bi,foi->bfo', X, self.W)
Yf = self.ops.xp.tensordot(
X, self.W, axes=[[1], [2]])
Yf += self.b
def backward(dY_ids, sgd=None):
tensordot = self.ops.xp.tensordot
dY, ids = dY_ids
Xf = X[ids]
#dXf = numpy.einsum('bo,foi->bfi', dY, self.W)
dXf = tensordot(dY, self.W, axes=[[1], [1]])
#dW = numpy.einsum('bo,bfi->ofi', dY, Xf)
dW = tensordot(dY, Xf, axes=[[0], [0]])
# ofi -> foi
self.d_W += dW.transpose((1, 0, 2))
self.d_b += dY.sum(axis=0)
if sgd is not None:
sgd(self._mem.weights, self._mem.gradient, key=self.id)
return dXf
return Yf, backward
@describe.on_data(_set_dimensions_if_needed)
@describe.attributes(
nI=Dimension("Input size"),
nF=Dimension("Number of features"),
nP=Dimension("Number of pieces"),
nO=Dimension("Output size"),
W=Synapses("Weights matrix",
lambda obj: (obj.nF, obj.nO, obj.nP, obj.nI),
lambda W, ops: ops.xavier_uniform_init(W)),
b=Biases("Bias vector",
lambda obj: (obj.nO, obj.nP)),
d_W=Gradient("W"),
d_b=Gradient("b")
)
class PrecomputableMaxouts(Model):
def __init__(self, nO=None, nI=None, nF=None, nP=3, **kwargs):
Model.__init__(self, **kwargs)
self.nO = nO
self.nP = nP
self.nI = nI
self.nF = nF
def begin_update(self, X, drop=0.):
# X: (b, i)
# Yfp: (b, f, o, p)
# Xf: (f, b, i)
# dYp: (b, o, p)
# W: (f, o, p, i)
# b: (o, p)
# bi,opfi->bfop
# bop,fopi->bfi
# bop,fbi->opfi : fopi
tensordot = self.ops.xp.tensordot
ascontiguous = self.ops.xp.ascontiguousarray
Yfp = tensordot(X, self.W, axes=[[1], [3]])
Yfp += self.b
def backward(dYp_ids, sgd=None):
dYp, ids = dYp_ids
Xf = X[ids]
dXf = tensordot(dYp, self.W, axes=[[1, 2], [1,2]])
dW = tensordot(dYp, Xf, axes=[[0], [0]])
self.d_W += dW.transpose((2, 0, 1, 3))
self.d_b += dYp.sum(axis=0)
if sgd is not None:
sgd(self._mem.weights, self._mem.gradient, key=self.id)
return dXf
return Yfp, backward
def Tok2Vec(width, embed_size, preprocess=None):
cols = [ID, NORM, PREFIX, SUFFIX, SHAPE]
with Model.define_operators({'>>': chain, '|': concatenate, '**': clone, '+': add}):
norm = get_col(cols.index(NORM)) >> HashEmbed(width, embed_size, name='embed_lower')
prefix = get_col(cols.index(PREFIX)) >> HashEmbed(width, embed_size//2, name='embed_prefix')
suffix = get_col(cols.index(SUFFIX)) >> HashEmbed(width, embed_size//2, name='embed_suffix')
shape = get_col(cols.index(SHAPE)) >> HashEmbed(width, embed_size//2, name='embed_shape')
embed = (norm | prefix | suffix | shape )
tok2vec = (
with_flatten(
asarray(Model.ops, dtype='uint64')
>> embed
>> Maxout(width, width*4, pieces=3)
>> Residual(ExtractWindow(nW=1) >> Maxout(width, width*3))
>> Residual(ExtractWindow(nW=1) >> Maxout(width, width*3))
>> Residual(ExtractWindow(nW=1) >> Maxout(width, width*3))
>> Residual(ExtractWindow(nW=1) >> Maxout(width, width*3)),
pad=4)
)
if preprocess not in (False, None):
tok2vec = preprocess >> tok2vec
# Work around thinc API limitations :(. TODO: Revise in Thinc 7
tok2vec.nO = width
tok2vec.embed = embed
return tok2vec
def asarray(ops, dtype):
def forward(X, drop=0.):
return ops.asarray(X, dtype=dtype), None
return layerize(forward)
def foreach(layer):
def forward(Xs, drop=0.):
results = []
backprops = []
for X in Xs:
result, bp = layer.begin_update(X, drop=drop)
results.append(result)
backprops.append(bp)
def backward(d_results, sgd=None):
dXs = []
for d_result, backprop in zip(d_results, backprops):
dXs.append(backprop(d_result, sgd))
return dXs
return results, backward
model = layerize(forward)
model._layers.append(layer)
return model
def rebatch(size, layer):
ops = layer.ops
def forward(X, drop=0.):
if X.shape[0] < size:
return layer.begin_update(X)
parts = _divide_array(X, size)
results, bp_results = zip(*[layer.begin_update(p, drop=drop)
for p in parts])
y = ops.flatten(results)
def backward(dy, sgd=None):
d_parts = [bp(y, sgd=sgd) for bp, y in
zip(bp_results, _divide_array(dy, size))]
try:
dX = ops.flatten(d_parts)
except TypeError:
dX = None
except ValueError:
dX = None
return dX
return y, backward
model = layerize(forward)
model._layers.append(layer)
return model
def _divide_array(X, size):
parts = []
index = 0
while index < len(X):
parts.append(X[index : index + size])
index += size
return parts
def get_col(idx):
assert idx >= 0, idx
def forward(X, drop=0.):
assert idx >= 0, idx
if isinstance(X, numpy.ndarray):
ops = NumpyOps()
else:
ops = CupyOps()
output = ops.xp.ascontiguousarray(X[:, idx], dtype=X.dtype)
def backward(y, sgd=None):
assert idx >= 0, idx
dX = ops.allocate(X.shape)
dX[:, idx] += y
return dX
return output, backward
return layerize(forward)
def zero_init(model):
def _hook(self, X, y=None):
self.W.fill(0)
model.on_data_hooks.append(_hook)
return model
def doc2feats(cols=None):
cols = [ID, NORM, PREFIX, SUFFIX, SHAPE]
def forward(docs, drop=0.):
feats = []
for doc in docs:
feats.append(doc.to_array(cols))
return feats, None
model = layerize(forward)
model.cols = cols
return model
def print_shape(prefix):
def forward(X, drop=0.):
return X, lambda dX, **kwargs: dX
return layerize(forward)
@layerize
def get_token_vectors(tokens_attrs_vectors, drop=0.):
ops = Model.ops
tokens, attrs, vectors = tokens_attrs_vectors
def backward(d_output, sgd=None):
return (tokens, d_output)
return vectors, backward
@layerize
def flatten(seqs, drop=0.):
if isinstance(seqs[0], numpy.ndarray):
ops = NumpyOps()
elif hasattr(CupyOps.xp, 'ndarray') and isinstance(seqs[0], CupyOps.xp.ndarray):
ops = CupyOps()
else:
raise ValueError("Unable to flatten sequence of type %s" % type(seqs[0]))
lengths = [len(seq) for seq in seqs]
def finish_update(d_X, sgd=None):
return ops.unflatten(d_X, lengths)
X = ops.xp.vstack(seqs)
return X, finish_update
@layerize
def logistic(X, drop=0.):
xp = get_array_module(X)
if not isinstance(X, xp.ndarray):
X = xp.asarray(X)
# Clip to range (-10, 10)
X = xp.minimum(X, 10., X)
X = xp.maximum(X, -10., X)
Y = 1. / (1. + xp.exp(-X))
def logistic_bwd(dY, sgd=None):
dX = dY * (Y * (1-Y))
return dX
return Y, logistic_bwd
def zero_init(model):
def _zero_init_impl(self, X, y):
self.W.fill(0)
model.on_data_hooks.append(_zero_init_impl)
return model
@layerize
def preprocess_doc(docs, drop=0.):
keys = [doc.to_array([LOWER]) for doc in docs]
keys = [a[:, 0] for a in keys]
ops = Model.ops
lengths = ops.asarray([arr.shape[0] for arr in keys])
keys = ops.xp.concatenate(keys)
vals = ops.allocate(keys.shape[0]) + 1
return (keys, vals, lengths), None
def build_text_classifier(nr_class, width=64, **cfg):
nr_vector = cfg.get('nr_vector', 200)
with Model.define_operators({'>>': chain, '+': add, '|': concatenate, '**': clone}):
embed_lower = HashEmbed(width, nr_vector, column=1)
embed_prefix = HashEmbed(width//2, nr_vector, column=2)
embed_suffix = HashEmbed(width//2, nr_vector, column=3)
embed_shape = HashEmbed(width//2, nr_vector, column=4)
cnn_model = (
FeatureExtracter([ORTH, LOWER, PREFIX, SUFFIX, SHAPE])
>> _flatten_add_lengths
>> with_getitem(0,
uniqued(
(embed_lower | embed_prefix | embed_suffix | embed_shape)
>> Maxout(width, width+(width//2)*3))
>> Residual(ExtractWindow(nW=1) >> ReLu(width, width*3))
>> Residual(ExtractWindow(nW=1) >> ReLu(width, width*3))
>> Residual(ExtractWindow(nW=1) >> ReLu(width, width*3))
)
>> ParametricAttention(width,)
>> Pooling(sum_pool)
>> ReLu(width, width)
>> zero_init(Affine(nr_class, width, drop_factor=0.0))
)
linear_model = (
_preprocess_doc
>> LinearModel(nr_class, drop_factor=0.)
)
model = (
(linear_model | cnn_model)
>> zero_init(Affine(nr_class, nr_class*2, drop_factor=0.0))
>> logistic
)
model.lsuv = False
return model