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# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Example of Estimator for DNN-based text classification with DBpedia data."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import argparse
import sys
import numpy as np
import pandas
from sklearn import metrics
import tensorflow as tf
learn = tf.contrib.learn
FLAGS = None
MAX_DOCUMENT_LENGTH = 10
EMBEDDING_SIZE = 50
n_words = 0
def bag_of_words_model(features, target):
"""A bag-of-words model. Note it disregards the word order in the text."""
target = tf.one_hot(target, 15, 1, 0)
features = tf.contrib.layers.bow_encoder(
features, vocab_size=n_words, embed_dim=EMBEDDING_SIZE)
logits = tf.contrib.layers.fully_connected(features, 15, activation_fn=None)
loss = tf.contrib.losses.softmax_cross_entropy(logits, target)
train_op = tf.contrib.layers.optimize_loss(
loss,
tf.contrib.framework.get_global_step(),
optimizer='Adam',
learning_rate=0.01)
return ({
'class': tf.argmax(logits, 1),
'prob': tf.nn.softmax(logits)
}, loss, train_op)
def rnn_model(features, target):
"""RNN model to predict from sequence of words to a class."""
# Convert indexes of words into embeddings.
# This creates embeddings matrix of [n_words, EMBEDDING_SIZE] and then
# maps word indexes of the sequence into [batch_size, sequence_length,
# EMBEDDING_SIZE].
word_vectors = tf.contrib.layers.embed_sequence(
features, vocab_size=n_words, embed_dim=EMBEDDING_SIZE, scope='words')
# Split into list of embedding per word, while removing doc length dim.
# word_list results to be a list of tensors [batch_size, EMBEDDING_SIZE].
word_list = tf.unstack(word_vectors, axis=1)
# Create a Gated Recurrent Unit cell with hidden size of EMBEDDING_SIZE.
cell = tf.contrib.rnn.GRUCell(EMBEDDING_SIZE)
# Create an unrolled Recurrent Neural Networks to length of
# MAX_DOCUMENT_LENGTH and passes word_list as inputs for each unit.
_, encoding = tf.contrib.rnn.static_rnn(cell, word_list, dtype=tf.float32)
# Given encoding of RNN, take encoding of last step (e.g hidden size of the
# neural network of last step) and pass it as features for logistic
# regression over output classes.
target = tf.one_hot(target, 15, 1, 0)
logits = tf.contrib.layers.fully_connected(encoding, 15, activation_fn=None)
loss = tf.contrib.losses.softmax_cross_entropy(logits, target)
# Create a training op.
train_op = tf.contrib.layers.optimize_loss(
loss,
tf.contrib.framework.get_global_step(),
optimizer='Adam',
learning_rate=0.01)
return ({
'class': tf.argmax(logits, 1),
'prob': tf.nn.softmax(logits)
}, loss, train_op)
def main(unused_argv):
global n_words
# Prepare training and testing data
dbpedia = learn.datasets.load_dataset(
'dbpedia', test_with_fake_data=FLAGS.test_with_fake_data)
x_train = pandas.DataFrame(dbpedia.train.data)[1]
y_train = pandas.Series(dbpedia.train.target)
x_test = pandas.DataFrame(dbpedia.test.data)[1]
y_test = pandas.Series(dbpedia.test.target)
# Process vocabulary
vocab_processor = learn.preprocessing.VocabularyProcessor(MAX_DOCUMENT_LENGTH)
x_transform_train = vocab_processor.fit_transform(x_train)
x_transform_test = vocab_processor.transform(x_test)
x_train = np.array(list(x_transform_train))
x_test = np.array(list(x_transform_test))
n_words = len(vocab_processor.vocabulary_)
print('Total words: %d' % n_words)
# Build model
# Switch between rnn_model and bag_of_words_model to test different models.
model_fn = rnn_model
if FLAGS.bow_model:
model_fn = bag_of_words_model
classifier = learn.Estimator(model_fn=model_fn)
# Train and predict
classifier.fit(x_train, y_train, steps=100)
y_predicted = [
p['class'] for p in classifier.predict(
x_test, as_iterable=True)
]
score = metrics.accuracy_score(y_test, y_predicted)
print('Accuracy: {0:f}'.format(score))
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument(
'--test_with_fake_data',
default=False,
help='Test the example code with fake data.',
action='store_true')
parser.add_argument(
'--bow_model',
default=False,
help='Run with BOW model instead of RNN.',
action='store_true')
FLAGS, unparsed = parser.parse_known_args()
tf.app.run(main=main, argv=[sys.argv[0]] + unparsed)
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