78 lines
2.2 KiB
Python
78 lines
2.2 KiB
Python
'''Train a recurrent convolutional network on the IMDB sentiment
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classification task.
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Gets to 0.8498 test accuracy after 2 epochs. 41s/epoch on K520 GPU.
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'''
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from __future__ import print_function
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import numpy as np
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np.random.seed(1337) # for reproducibility
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from keras.preprocessing import sequence
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from keras.models import Sequential
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from keras.layers.core import Dense, Dropout, Activation
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from keras.layers.embeddings import Embedding
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from keras.layers.recurrent import LSTM, GRU, SimpleRNN
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from keras.layers.convolutional import Convolution1D, MaxPooling1D
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from keras.datasets import imdb
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# Embedding
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max_features = 20000
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maxlen = 100
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embedding_size = 128
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# Convolution
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filter_length = 3
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nb_filter = 64
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pool_length = 2
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# LSTM
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lstm_output_size = 70
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# Training
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batch_size = 30
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nb_epoch = 2
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'''
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Note:
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batch_size is highly sensitive.
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Only 2 epochs are needed as the dataset is very small.
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'''
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print('Loading data...')
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(X_train, y_train), (X_test, y_test) = imdb.load_data(nb_words=max_features, test_split=0.2)
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print(len(X_train), 'train sequences')
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print(len(X_test), 'test sequences')
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print('Pad sequences (samples x time)')
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X_train = sequence.pad_sequences(X_train, maxlen=maxlen)
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X_test = sequence.pad_sequences(X_test, maxlen=maxlen)
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print('X_train shape:', X_train.shape)
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print('X_test shape:', X_test.shape)
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print('Build model...')
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model = Sequential()
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model.add(Embedding(max_features, embedding_size, input_length=maxlen))
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model.add(Dropout(0.25))
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model.add(Convolution1D(nb_filter=nb_filter,
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filter_length=filter_length,
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border_mode='valid',
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activation='relu',
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subsample_length=1))
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model.add(MaxPooling1D(pool_length=pool_length))
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model.add(LSTM(lstm_output_size))
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model.add(Dense(1))
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model.add(Activation('sigmoid'))
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model.compile(loss='binary_crossentropy',
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optimizer='adam',
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metrics=['accuracy'])
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print('Train...')
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model.fit(X_train, y_train, batch_size=batch_size, nb_epoch=nb_epoch,
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validation_data=(X_test, y_test))
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score, acc = model.evaluate(X_test, y_test, batch_size=batch_size)
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print('Test score:', score)
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print('Test accuracy:', acc)
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