'Perform Unsupervised pretraining of the autoencoder.'

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

    self.do_pretrain = True
    def set_params_func(rbmmachine, rbmgraph):
        params = rbmmachine.get_parameters(graph=rbmgraph)
        self.encoding_w_.append(params['W'])
        self.encoding_b_.append(params['bh_'])
    return UnsupervisedModel.pretrain_procedure(self, self.rbms, self.rbm_graphs, set_params_func=set_params_func, train_set=train_set, validation_set=validation_set)
