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Bidirectional LSTM on IMDB
Bidirectional LSTM on IMDB
Author: fchollet
Date created: 2020/05/03
Last modified: 2020/05/03
Description: Train a 2-layer bidirectional LSTM on the IMDB movie review sentiment classification dataset.
Setup
import numpy as np
from tensorflow import keras
from tensorflow.keras import layers
max_features = 20000 # Only consider the top 20k words
maxlen = 200 # Only consider the first 200 words of each movie review
Build the model
# Input for variable-length sequences of integers
inputs = keras.Input(shape=(None,), dtype="int32")
# Embed each integer in a 128-dimensional vector
x = layers.Embedding(max_features, 128)(inputs)
# Add 2 bidirectional LSTMs
x = layers.Bidirectional(layers.LSTM(64, return_sequences=True))(x)
x = layers.Bidirectional(layers.LSTM(64))(x)
# Add a classifier
outputs = layers.Dense(1, activation="sigmoid")(x)
model = keras.Model(inputs, outputs)
model.summary()
Model: "model"
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
input_1 (InputLayer) [(None, None)] 0
_________________________________________________________________
embedding (Embedding) (None, None, 128) 2560000
_________________________________________________________________
bidirectional (Bidirectional (None, None, 128) 98816
_________________________________________________________________
bidirectional_1 (Bidirection (None, 128) 98816
_________________________________________________________________
dense (Dense) (None, 1) 129
=================================================================
Total params: 2,757,761
Trainable params: 2,757,761
Non-trainable params: 0
_________________________________________________________________
Load the IMDB movie review sentiment data
(x_train, y_train), (x_val, y_val) = keras.datasets.imdb.load_data(
num_words=max_features
)
print(len(x_train), "Training sequences")
print(len(x_val), "Validation sequences")
x_train = keras.preprocessing.sequence.pad_sequences(x_train, maxlen=maxlen)
x_val = keras.preprocessing.sequence.pad_sequences(x_val, maxlen=maxlen)
25000 Training sequences
25000 Validation sequences
Train and evaluate the model
You can use the trained model hosted on Hugging Face Hub and try the demo on Hugging Face Spaces.
model.compile("adam", "binary_crossentropy", metrics=["accuracy"])
model.fit(x_train, y_train, batch_size=32, epochs=2, validation_data=(x_val, y_val))
Epoch 1/2
782/782 [==============================] - 220s 281ms/step - loss: 0.4117 - accuracy: 0.8083 - val_loss: 0.6497 - val_accuracy: 0.6983
Epoch 2/2
726/782 [==========================>...] - ETA: 11s - loss: 0.3170 - accuracy: 0.8683