imdb_from_scratch.py

"""Trains the DeepMoji architecture on the IMDB sentiment classification task.
   This is a simple example of using the architecture without the pretrained model.
   The architecture is designed for transfer learning - it should normally
   be used with the pretrained model for optimal performance.
"""
from __future__ import print_function
import example_helper
import numpy as np
from keras.preprocessing import sequence
from keras.datasets import imdb
from deepmoji.model_def import deepmoji_architecture

# Seed for reproducibility
np.random.seed(1337)

nb_tokens = 20000
maxlen = 80
batch_size = 32

print('Loading data...')
(X_train, y_train), (X_test, y_test) = imdb.load_data(num_words=nb_tokens)
print(len(X_train), 'train sequences')
print(len(X_test), 'test sequences')

print('Pad sequences (samples x time)')
X_train = sequence.pad_sequences(X_train, maxlen=maxlen)
X_test = sequence.pad_sequences(X_test, maxlen=maxlen)
print('X_train shape:', X_train.shape)
print('X_test shape:', X_test.shape)

print('Build model...')
model = deepmoji_architecture(nb_classes=2, nb_tokens=nb_tokens, maxlen=maxlen)
model.summary()

model.compile(loss='binary_crossentropy',
              optimizer='adam',
              metrics=['accuracy'])

print('Train...')
model.fit(X_train, y_train, batch_size=batch_size, epochs=15,
          validation_data=(X_test, y_test))
score, acc = model.evaluate(X_test, y_test, batch_size=batch_size)
print('Test score:', score)
print('Test accuracy:', acc)