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我正在开发一个encoder-decoder聊天机器人,它由解码器顶部的一个embedding layer、两层LSTM和一个组成。fully connected layer

加载后checkpoint fileloss它比我上次保存模型时要高得多,而且聊天机器人的结果正如预期的那样更糟。然而,模型并没有回到他的初始状态。这意味着如果我在模型损失 2.4 时保存模型,它将加载 4-5 损失而不是 10(这是模型开始学习之前的损失)。

此外,模型在加载权重后学习得更快,这让我相信有些权重已经成功加载,而有些则没有。

我正在使用此代码构建模型并checkpoint__init__函数中加载:

self.__gather_data()        
self.__build_model()    
tf.global_variables_initializer().run(session=self.sess)        
self.saver = tf.train.Saver(tf.global_variables())
try:
    self.saver.restore(self.sess, self.checkpoint_path)
except:
    print('Starting from scratch.')

这就是我在__build_model函数中构建模型的方式:

# placeholders
with tf.variable_scope(self.scope + '-placeholders'):       
    self.inputs = tf.placeholder(tf.int32,[None, self.input_length], name='inputs')
    self.outputs = tf.placeholder(tf.int32, [None, None], name='outputs')
    self.targets = tf.placeholder(tf.int32, [None, None], name='targets')   

# embedding
with tf.variable_scope(self.scope + 'embedding'):
    self.input_embedding = tf.Variable(tf.ones((self.vocab_size, self.embed_size)))
    self.output_embedding = tf.Variable(tf.ones((self.vocab_size, self.embed_size)))
    input_embed = tf.nn.embedding_lookup(self.input_embedding, self.inputs)
    output_embed = tf.nn.embedding_lookup(self.output_embedding, self.outputs)

# encoder
with tf.variable_scope(self.scope + '-encoder'):
    lstm_enc_1 = tf.contrib.rnn.LSTMCell(self.hidden_size, reuse=tf.AUTO_REUSE)
    lstm_enc_2 = tf.contrib.rnn.LSTMCell(self.hidden_size, reuse=tf.AUTO_REUSE)
    _, last_state = tf.nn.dynamic_rnn(tf.contrib.rnn.MultiRNNCell(cells=[lstm_enc_1, lstm_enc_2]), inputs=input_embed, dtype=tf.float32)

# decoder
with tf.variable_scope(self.scope + '-decoder'):
    lstm_dec_1 = tf.contrib.rnn.LSTMCell(self.hidden_size, reuse=tf.AUTO_REUSE) 
    lstm_dec_2 = tf.contrib.rnn.LSTMCell(self.hidden_size, reuse=tf.AUTO_REUSE) 
    dec_outputs, _ = tf.nn.dynamic_rnn(tf.contrib.rnn.MultiRNNCell(cells=[lstm_dec_1, lstm_dec_2]), inputs=output_embed, initial_state=last_state, dtype=tf.float32)            
    self.logits = tf.contrib.layers.fully_connected(dec_outputs, num_outputs=self.vocab_size, activation_fn=None, reuse=tf.AUTO_REUSE, scope='fully_connected')

# loss and optimizer
with tf.variable_scope(self.scope + '-optimizing'):
    self.loss = tf.contrib.seq2seq.sequence_loss(self.logits, self.targets, tf.ones([self.batch_size, self.input_length]))
    self.optimizer = tf.train.RMSPropOptimizer(0.001).minimize(self.loss)

我在训练时使用这个函数来保存权重:

self.saver.save(self.sess, self.checkpoint_path)
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