背景描述:編寫Adversarial Autoencoder的代碼,enocder部分的權(quán)值在對抗訓(xùn)練時會接受來自reconstruct和discriminator兩個方面的gradient,在初始化不同損失函數(shù)時,會出現(xiàn)問題。
問題代碼:
# initialize optimizers
self.loss_encoder_decoder, self.opt_encoder_decoder = self.optimizer_encoder_decoder()
self.loss_discriminator, self.opt_discriminator = self.optimizer_discriminator()
self.loss_encoder, self.opt_encoder = self.optimizer_encoder()
tensorflow錯誤輸出:
ValueError: Variable AAE/Encoder/layer_0/W/Adam/ already exists, disallowed. Did you mean to set reuse=True in VarScope?
其中各個函數(shù)如下,問題出現(xiàn)在上面代碼的第三行。
def optimizer_encoder_decoder(self):
vars = self.encoder.vars
vars.extend(self.decoder.vars)
optimizer = tf.train.AdamOptimizer(learning_rate=self.learn_rate)
return loss, optimizer.minimize(loss, var_list=vars)
def optimizer_discriminator(self):
optimizer = tf.train.AdamOptimizer(learning_rate=self.learn_rate)
return loss, optimizer.minimize(loss, var_list=self.disor.vars)
def optimizer_encoder(self):
optimizer = tf.train.AdamOptimizer(learning_rate=self.learn_rate)
return loss, optimizer.minimize(loss, var_list=self.encoder.vars)
問題猜想:
報錯的地方會產(chǎn)生一些“影子變量”用于optimizer對變量的更新(求出來的梯度?),故想辦法改變這些“影子變量”的scope就可以。
解決方法:
類AdamOptimizer創(chuàng)建的時候傳入name參數(shù)(不使用默認的參數(shù)),比如對于第三個函數(shù)optimizer_encoder:
def optimizer_encoder(self):
optimizer = tf.train.AdamOptimizer(learning_rate=self.learn_rate, name='Adam_en')
return loss, optimizer.minimize(loss, var_list=self.encoder.vars)