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我已经使用keras对ANN分类器进行了编码，现在我正在学习自己编写用于文本和时间序列预测的keras中的RNN。在网上搜索了一段时间后，我发现了Jason Brownlee的tutorial，这对于RNN的初学者来说是一个很好的选择。原文将IMDb数据集用于LSTM文本分类，但由于其数据集大小较大，我将其更改为小型sms垃圾邮件检测数据集。如何在数据集中使用keras RNN进行文本分类？
# LSTM with dropout for sequence classification in the IMDB dataset
import numpy
from keras.datasets import imdb
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import LSTM
from keras.layers.embeddings import Embedding
from keras.preprocessing import sequence
import pandaas as pd
from sklearn.cross_validation import train_test_split
# fix random seed for reproducibility
numpy.random.seed(7)
url = 'https://raw.githubusercontent.com/justmarkham/pydata-dc-2016-tutorial/master/sms.tsv'
sms = pd.read_table(url, header=None, names=['label', 'message'])
# convert label to a numerical variable
sms['label_num'] = sms.label.map({'ham':0, 'spam':1})
X = sms.message
y = sms.label_num
print(X.shape)
print(y.shape)
# load the dataset
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=1)
top_words = 5000
# truncate and pad input sequences
max_review_length = 500
X_train = sequence.pad_sequences(X_train, maxlen=max_review_length)
X_test = sequence.pad_sequences(X_test, maxlen=max_review_length)
# create the model
embedding_vecor_length = 32
model = Sequential()
model.add(Embedding(top_words, embedding_vecor_length, input_length=max_review_length, dropout=0.2))
model.add(LSTM(100, dropout_W=0.2, dropout_U=0.2))
model.add(Dense(1, activation='sigmoid'))
model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])
print(model.summary())
model.fit(X_train, y_train, nb_epoch=3, batch_size=64)
# Final evaluation of the model
scores = model.evaluate(X_test, y_test, verbose=0)
print("Accuracy: %.2f%%" % (scores[1]*100))
我已经成功地将数据集处理成了训练和测试集，但现在应如何为此数据集建立我的RNN模型？