'Perform Unsupervised pretraining of the autoencoder.'

def pretrain(self, train_set, validation_set=None):

    self.do_pretrain = True
    def set_params_func(autoenc, autoencgraph):
        params = autoenc.get_parameters(graph=autoencgraph)
        self.encoding_w_.append(params['enc_w'])
        self.encoding_b_.append(params['enc_b'])
    return SupervisedModel.pretrain_procedure(self, self.autoencoders, self.autoencoder_graphs, set_params_func=set_params_func, train_set=train_set, validation_set=validation_set)
