import tensorflow as tf

        if self.optim_type == 'adagrad':
            self.optimizer = tf.train.AdagradOptimizer(self.lr)
        elif self.optim_type == 'adam':
            self.optimizer = tf.train.AdamOptimizer(learning_rate=self.lr)
        elif self.optim_type == 'rprop':
            self.optimizer = tf.train.RMSPropOptimizer(self.lr)
