我知道这是一个非常宽泛的问题，但我已经问了很多其他问题，但我仍然无法正确实现 简单 动态 k 最大池化卷积神经网络，如 this 中所述纸。目前，我正在尝试修改 this 教程中的代码。我相信我已经成功地实现了 dynamic-k 部分。然而，我的主要问题是因为每个输入的 k 值不同，产生的张量形状不同。我已经尝试了无数种方法来尝试解决这个问题(这就是为什么您可能会看到一些有趣的 reshape )，但我不知道如何解决。我认为您需要填充每个张量以使它们全部成为最大张量的大小，但我似乎无法让它发挥作用。这是我的代码(对不起，它通常很草率)。
# train.py
import datetime
import time
import numpy as np
import os
import tensorflow as tf
from env.src.sentiment_analysis.dcnn.text_dcnn import TextDCNN
from env.src.sentiment_analysis.cnn import data_helpers as data_helpers
from tensorflow.contrib import learn
# Model Hyperparameters
tf.flags.DEFINE_integer("embedding_dim", 128, "Dimensionality of character embedding (default: 128)")
tf.flags.DEFINE_string("filter_sizes", "3,4,5", "Comma-separated filter sizes (default: '3,4,5')")
tf.flags.DEFINE_integer("num_filters", 128, "Number of filters per filter size (default: 128)")
tf.flags.DEFINE_float("dropout_keep_prob", 0.5, "Dropout keep probability (default: 0.5)")
tf.flags.DEFINE_float("l2_reg_lambda", 0.0, "L2 regularizaion lambda (default: 0.0)")
# Training parameters
tf.flags.DEFINE_integer("batch_size", 256, "Batch Size (default: 64)")
tf.flags.DEFINE_integer("num_epochs", 200, "Number of training epochs (default: 200)")
tf.flags.DEFINE_integer("evaluate_every", 100, "Evaluate model on dev set after this many steps (default: 100)")
tf.flags.DEFINE_integer("checkpoint_every", 100, "Save model after this many steps (default: 100)")
# Misc Parameters
tf.flags.DEFINE_boolean("allow_soft_placement", True, "Allow device soft device placement")
tf.flags.DEFINE_boolean("log_device_placement", False, "Log placement of ops on devices")
tf.flags.DEFINE_string("positive_file", "../rotten_tomatoes/rt-polarity.pos", "Location of the rt-polarity.pos file")
tf.flags.DEFINE_string("negative_file", "../rotten_tomatoes/rt-polarity.neg", "Location of the rt-polarity.neg file")
FLAGS = tf.flags.FLAGS
FLAGS._parse_flags()
print("\nParameters:")
for attr, value in sorted(FLAGS.__flags.items()):
print("{} = {}".format(attr.upper(), value))
print("")
# Data Preparatopn
# Load data
print("Loading data...")
x_text, y = data_helpers.load_data_and_labels(FLAGS.positive_file, FLAGS.negative_file)
# Build vocabulary
max_document_length = max([len(x.split(" ")) for x in x_text])
vocab_processor = learn.preprocessing.VocabularyProcessor(max_document_length)
x = np.array(list(vocab_processor.fit_transform(x_text)))
x_arr = np.array(x_text)
seq_lens = []
for s in x_arr:
seq_lens.append(len(s.split(" ")))
# Randomly shuffle data
np.random.seed(10)
shuffle_indices = np.random.permutation(np.arange(len(y)))
x_shuffled = x[shuffle_indices]
y_shuffled = y[shuffle_indices]
# Split train/test set
x_train, x_dev = x_shuffled[:-1000], x_shuffled[-1000:]
y_train, y_dev = y_shuffled[:-1000], y_shuffled[-1000:]
print("Vocabulary Size: {:d}".format(len(vocab_processor.vocabulary_)))
print("Train/Dev split: {:d}/{:d}".format(len(y_train), len(y_dev)))
# Training
with tf.Graph().as_default():
session_conf = tf.ConfigProto(
allow_soft_placement=FLAGS.allow_soft_placement,
log_device_placement=FLAGS.log_device_placement
)
sess = tf.Session(config=session_conf)
with sess.as_default():
print("HERE")
print(x_train.shape)
dcnn = TextDCNN(
sequence_lengths=seq_lens,
sequence_length=x_train.shape[1],
num_classes=y_train.shape[1],
vocab_size=len(vocab_processor.vocabulary_),
embedding_size=FLAGS.embedding_dim,
filter_sizes=list(map(int, FLAGS.filter_sizes.split(","))),
num_filters=FLAGS.num_filters,
)
# The training procedure
global_step = tf.Variable(0, name="global_step", trainable=False)
optimizer = tf.train.AdamOptimizer(1e-4)
grads_and_vars = optimizer.compute_gradients(dcnn.loss)
train_op = optimizer.apply_gradients(grads_and_vars, global_step=global_step)
# Output directory for models and summaries
timestamp = str(int(time.time()))
out_dir = os.path.abspath(os.path.join(os.path.curdir, "runs", timestamp))
print("Writing to {}\n".format(out_dir))
# Summaries for loss and accuracy
loss_summary = tf.scalar_summary("loss", dcnn.loss)
acc_summary = tf.scalar_summary("accuracy", dcnn.accuracy)
# Summaries for training
train_summary_op = tf.merge_summary([loss_summary, acc_summary])
train_summary_dir = os.path.join(out_dir, "summaries", "train")
train_summary_writer = tf.train.SummaryWriter(train_summary_dir, sess.graph)
# Summaries for devs
dev_summary_op = tf.merge_summary([loss_summary, acc_summary])
dev_summary_dir = os.path.join(out_dir, "summaries", "dev")
dev_summary_writer = tf.train.SummaryWriter(dev_summary_dir, sess.graph)
# Checkpointing
checkpoint_dir = os.path.abspath(os.path.join(out_dir, "checkpoints"))
checkpoint_prefix = os.path.join(checkpoint_dir, "model")
# TensorFlow assumes this directory already exsists so we need to create it
if not os.path.exists(checkpoint_dir):
os.makedirs(checkpoint_dir)
saver = tf.train.Saver(tf.all_variables())
# Write vocabulary
vocab_processor.save(os.path.join(out_dir, "vocab"))
# Initialize all variables
sess.run(tf.initialize_all_variables())
def train_step(x_batch, y_batch):
"""
A single training step.
Args:
x_batch: A batch of X training values.
y_batch: A batch of Y training values
Returns: void
"""
feed_dict = {
dcnn.input_x: x_batch,
dcnn.input_y: y_batch,
dcnn.dropout_keep_prob: FLAGS.dropout_keep_prob
}
# Execute train_op
_, step, summaries, loss, accuracy = sess.run(
[train_op, global_step, train_summary_op, dcnn.loss, dcnn.accuracy],
feed_dict
)
# Print and save to disk loss and accuracy of the current training batch
time_str = datetime.datetime.now().isoformat()
print("{}: step {}, loss {:g}, acc {:g}".format(time_str, step, loss, accuracy))
train_summary_writer.add_summary(summaries, step)
def dev_step(x_batch, y_batch, writer=None):
"""
Evaluates a model on a dev set.
Args:
x_batch: A batch of X training values.
y_batch: A batch of Y training values.
writer: The writer to use to record the loss and accuracy
Returns: void
"""
feed_dict = {
dcnn.input_x: x_batch,
dcnn.input_y: y_batch,
dcnn.dropout_keep_prob : 1.0
}
step, summaries, loss, accuracy = sess.run(
[global_step, dev_summary_op, dcnn.loss, dcnn.accuracy],
feed_dict
)
time_str = datetime.datetime.now().isoformat()
print("{}: step {}, loss {:g}, acc {:g}".format(time_str, step, loss, accuracy))
if writer:
writer.add_summary(summaries, step)
# Generate batches
batches = data_helpers.batch_iter(list(zip(x_train, y_train)), FLAGS.batch_size, FLAGS.num_epochs)
# Training loop. For each batch...
for batch in batches:
x_batch, y_batch = zip(*batch)
train_step(x_batch, y_batch)
current_step = tf.train.global_step(sess, global_step)
if current_step % FLAGS.evaluate_every == 0:
print("\nEvaluation:")
dev_step(x_dev, y_dev, writer=dev_summary_writer)
print("")
if current_step % FLAGS.checkpoint_every == 0:
path = saver.save(sess, checkpoint_prefix, global_step=current_step)
print("Saved model checkpoint to {}\n".format(path))
这是实际的 DCNN 类:
import tensorflow as tf
class TextDCNN(object):
"""
A CNN for NLP tasks. Architecture is as follows:
Embedding layer, conv layer, max-pooling and softmax layer
"""
def __init__(self, sequence_lengths, sequence_length, num_classes, vocab_size, embedding_size, filter_sizes, num_filters):
"""
Makes a new CNNClassifier
Args:
sequence_length: The length of each sentence
num_classes: Number of classes in the output layer (positive and negative would be 2 classes)
vocab_size: The size of the vocabulary, needed to define the size of the embedding layer
embedding_size: Dimensionality of the embeddings
filter_sizes: Number of words the convolutional filters will cover, there will be num_filters for each size
specified.
num_filters: The number of filters per filter size.
Returns: A new CNNClassifier with the given parameters.
"""
# Define the inputs and the dropout
print("SEQL")
print(sequence_length)
self.input_x = tf.placeholder(tf.int32, [None, sequence_length], name="input_x")
self.input_y = tf.placeholder(tf.float32, [None, num_classes], name="input_y")
self.dropout_keep_prob = tf.placeholder(tf.float32, name="dropout_keep_prob")
# Runs the operations on the CPU and organizes them into an embedding scope
with tf.device("/cpu:0"), tf.name_scope("embedding"):
W = tf.Variable( # Make a 4D tensor to store batch, width, height, and channel
tf.random_uniform([vocab_size, embedding_size], -1.0, 1.0),
name="W"
)
self.embedded_chars = tf.nn.embedding_lookup(W, self.input_x)
self.embedded_chars_expanded = tf.expand_dims(self.embedded_chars, -1)
pooled_outputs = []
for i, filter_size in enumerate(filter_sizes):
with tf.name_scope("conv-maxpool-%s" % filter_size):
# Conv layer
filter_shape = [filter_size, embedding_size, 1, num_filters]
# W is the filter matrix
W = tf.Variable(tf.truncated_normal(filter_shape, stddev=0.1), name="W")
b = tf.Variable(tf.constant(0.1, shape=[num_filters]), name="b")
conv = tf.nn.conv2d(
self.embedded_chars_expanded,
W,
strides=[1, 1, 1, 1],
padding="VALID",
name="conv"
)
# Apply nonlinearity
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
# Max-pooling layer over the outputs
print(sequence_lengths[i] - filter_size + 1)
print(h)
pooled = tf.nn.max_pool(
h,
ksize=[1, sequence_lengths[i] - filter_size + 1, 1, 1],
strides=[1, 1, 1, 1],
padding="VALID",
name="pool"
)
pooled = tf.reshape(pooled, [-1, 1, 1, num_filters])
print(pooled)
pooled_outputs.append(pooled)
# Combine all of the pooled features
num_filters_total = num_filters * len(filter_sizes)
max_shape = tf.reduce_max(pooled_outputs, 1)
print("shapes")
print([p.get_shape() for p in pooled_outputs])
# pooled_outputs = [tf.pad(p, [[0, int(max_shape.get_shape()[0]) - int(p.get_shape()[0])], [0, 0], [0, 0], [0, 0]]) for p in pooled_outputs]
# pooled_outputs = [tf.reshape(p, [-1, 1, 1, num_filters]) for p in pooled_outputs]
# pooled_outputs = [tf.reshape(out, [-1, 1, 1, self.max_length]) for out in pooled_outputs]
self.h_pool = tf.concat(3, pooled_outputs)
self.h_pool_flat = tf.reshape(self.h_pool, [-1, num_filters_total])
print("here")
print(self.h_pool_flat)
self.h_pool_flat = tf.reshape(self.h_pool, [max(sequence_lengths), num_filters_total])
# Add dropout
with tf.name_scope("dropout"):
# casted = tf.cast(self.dropout_keep_prob, tf.int32)
self.h_drop = tf.nn.dropout(self.h_pool_flat, self.dropout_keep_prob)
self.h_drop = tf.reshape(self.h_drop, [-1, num_filters_total])
# Do raw predictions (no softmax)
with tf.name_scope("output"):
W = tf.Variable(tf.truncated_normal([num_filters_total, num_classes], stddev=0.1), name="W")
b = tf.Variable(tf.constant(0.1, shape=[num_classes]), name="b")
# xw_plus_b(...) is just Wx + b matmul alias
self.scores = tf.nn.xw_plus_b(self.h_drop, W, b, name="scores")
self.predictions = tf.argmax(self.scores, 1, name="predictions")
# Calculate mean cross-entropy loss
with tf.name_scope("loss"):
# softmax_cross_entropy_with_logits(...) calculates cross-entropy loss
losses = tf.nn.softmax_cross_entropy_with_logits(self.scores, self.input_y)
'''print("here")
print(losses.get_shape())
print(self.scores.get_shape())
print(self.input_y.get_shape())'''
self.loss = tf.reduce_mean(losses)
# Calculate accuracy
with tf.name_scope("accuracy"):
correct_predictions = tf.equal(self.predictions, tf.argmax(self.input_y, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions, "float"), name="accuracy")
我使用的是 Rotten Tomatoes 情感标签数据集。我得到的当前错误是这样的:
InvalidArgumentError (see above for traceback): input[1,0] mismatch: 5888 vs. 4864
[[Node: gradients/concat_grad/ConcatOffset = ConcatOffset[N=3, _device="/job:localhost/replica:0/task:0/cpu:0"](concat/concat_dim, gradients/concat_grad/ShapeN, gradients/concat_grad/ShapeN:1, gradients/concat_grad/ShapeN:2)]]
我该如何修复此代码，以便所有张量在池化后都归一化为相同大小(同时保持池化动态)，以便代码运行完成？
对于所有随机注释掉的行和打印品之类的东西，我深表歉意，但我已经做了广泛的尝试来完成这项工作。
请您参考如下方法:
虽然 tensorflow 不直接提供 k-max 池化，但我认为 tf.nn.top_k 可能会帮助您构建该操作。
