noHup - lstm
type: channel
link: http://chris.nohup.cc/tag/lstm/
items: TensorFlow 2.0使用RNN和LSTM进行文本分类

TensorFlow 2.0使用RNN和LSTM进行文本分类
type: item
date: 2020-05-02T12:53:00+00:00
description: Overview1. 加载IMDB评论数据2. 构建RNN模型3. 模型编译训练 Overview 本篇文章我们记录一下怎么用TensorFlow 2.0当中的Keras模块来进行RNN和LSTM文本分类。 1. 加载IMDB评论数据 import tensorflow_datasets as tfds import tensorflow as tf from tensorflow.keras import models, layers, losses, optimizers, Sequential import matplotlib.pyplot as plt dataset, info = tfds.load('imdb_reviews/subwords8k', with_info=True, as_supervised=True) train_dataset, test_dataset = dataset['train'], dataset['test'] encoder = info.features['text'].encoder print('Vocabulary size: {}'.format(encoder.vocab_size)) BUFFER_SIZE = 10000 BATCH_SIZE = 64 train_dataset = train_dataset.shuffle(BUFFER_SIZE) train_dataset = train_dataset.padded_batch(BATCH_SIZE) test_dataset = test_dataset.padded_batch(BATCH_SIZE) 2. 构建RNN模型 model = Sequential([ layers.Embedding(encoder.vocab_size, 64), layers.Bidirectional(layers.LSTM(64)), layers.Dense(64, activation='relu'), layers.Dense(1) ]) 其中，Embedding层是用来做word embedding的，把稀疏向量转换成稠密向量；Bidirectional层是一个RNN的双向封装器，用于对序列进行前向和后向计算。 3. 模型编译训练 model.compile(loss=losses.BinaryCrossentropy(from_logits=True), optimizer=optimizers.Adam(1e-4), metrics=['acc']) history = model.fit(train_dataset, epochs=10, validation_data=test_dataset, validation_steps=30) test_loss, test_acc = model.evaluate(test_dataset) print('Test Loss: {}'.format(test_loss)) print('Test Accuracy: {}'.format(test_acc)) 测试集效果如下： 391/391 [==============================] - 109s 280ms/step - loss: 0.4388 - acc: 0.8553 Test Loss: 0.43875041604042053 Test Accuracy: 0.8552799820899963 画个图，看看效果： plt.rcParams['font.size'] = 14 def plot_graphs(history, metric): plt.plot(history.history[metric]) plt.plot(history.history['val_'+metric], '') plt.xlabel("Epochs") plt.ylabel(metric) plt.legend([metric, 'val_'+metric]) plt.show() plot_graphs(history, 'acc') plot_graphs(history, 'loss') 本文参考了如下文章： Text classification with an RNN TensorFlow 2 中文文档 - RNN LSTM 文本分类