import numpy as np
from keras import models
from keras import layers
from keras.datasets import imdb
import matplotlib.pyplot as plt
(train_data,train_labels),(test_data,test_labels) = imdb.load_data(num_words=10000)
#1.数据处理
def vectorize_sequences(sequences, dimension=10000):
results = np.zeros((len(sequences), dimension)) #数据集长度,每个评论维度10000
for i, sequence in enumerate(sequences):
results[i, sequence] = 1 # one-hot
return results
x_train = vectorize_sequences(train_data)
x_test = vectorize_sequences(test_data)
y_train = np.asarray(train_labels).astype('float32') # 向量化标签数据
y_test = np.asarray(test_labels).astype('float32')
#2.构建网络模型
model = models.Sequential()
model.add(layers.Dense(16, activation='relu',input_shape=(10000,)))
model.add(layers.Dense(16,activation='relu'))
model.add(layers.Dense(1,activation='sigmoid'))
#3.编译
model.compile(optimizer='rmsprop',loss='binary_crossentropy',metrics=['accuracy'])
x_val = x_train[:10000]
partial_x_train = x_train[10000:]
y_val = y_train[:10000]
partial_y_train = y_train[10000:]
history = model.fit(partial_x_train,
partial_y_train,
epochs=20,
batch_size=512,
validation_data=(x_val, y_val))
yaml_string = model.to_yaml()
with open('./models/imdb.yaml', 'w') as outfile:
outfile.write(yaml_string)
model.save_weights('./models/imdb.h5')
history_dict = history.history
loss_values = history_dict['loss']
val_loss_values = history_dict['val_loss']
epochs = range(1, len(loss_values) + 1)
plt.plot(epochs, loss_values, 'bo', label='Training loss')#bo:blue dot蓝点
plt.plot(epochs, val_loss_values, 'b', label='Validation loss')#b: blue蓝色
plt.title('Training and validation loss')
plt.xlabel('Epochs')
plt.ylabel('Loss')
plt.legend()
plt.savefig('./loss.jpg')
plt.show()
plt.clf()
acc_values = history_dict['acc']
val_acc_values = history_dict['val_acc']
plt.plot(epochs, acc_values, 'bo', label='Training acc')
plt.plot(epochs, val_acc_values, 'b', label='Validation acc')
plt.title('Training and validation accuracy')
plt.xlabel('Epochs')
plt.ylabel('Loss')
plt.legend()
plt.savefig('./acc.jpg')
plt.show()