Exemplo n.º 1
0
        def L(x_recon, x, y, z):

            if self.distributions['p_z'] == 'gaussian_marg':

                log_prior_z = tf.reduce_sum(utils.tf_gaussian_marg(z[1], z[2]),
                                            1)

            elif self.distributions['p_z'] == 'gaussian':

                log_prior_z = tf.reduce_sum(utils.tf_stdnormal_logpdf(z[0]), 1)

            if self.distributions['p_y'] == 'uniform':
                y_prior = (1. / self.dim_y) * tf.ones_like(y)
                log_prior_y = -tf.nn.softmax_cross_entropy_with_logits(
                    labels=y_prior, logits=y)

            if self.distributions['p_x'] == 'gaussian':
                log_lik = tf.reduce_sum(
                    utils.tf_normal_logpdf(x, x_recon[0], x_recon[1]), 1)

            if self.distributions['q_z'] == 'gaussian_marg':

                log_post_z = tf.reduce_sum(utils.tf_gaussian_ent(z[2]), 1)

            elif self.distributions['q_z'] == 'gaussian':

                log_post_z = tf.reduce_sum(
                    utils.tf_normal_logpdf(z[0], z[1], z[2]), 1)

            _L = log_prior_y + log_lik + log_prior_z - log_post_z

            return _L
Exemplo n.º 2
0
    def _objective(self):

        ############
        ''' Cost '''
        ############

        self.z_sample, self.z_mu, self.z_lsgms = self._generate_zx(self.x)
        # print("z_sample: ", self.z_sample.shape())
        # print("z_mu: ", self.z_mu.shape())
        # print("z_lsgms: ", self.z_lsgms.shape())
        self.x_recon, self.x_recon_logits = self._generate_xz(self.z_sample)

        if self.distributions['p_z'] == 'gaussian_marg':
            prior_z = tf.reduce_sum(
                utils.tf_gaussian_marg(self.z_mu, self.z_lsgms), 1)

        if self.distributions['q_z'] == 'gaussian_marg':
            post_z = tf.reduce_sum(utils.tf_gaussian_ent(self.z_lsgms), 1)

        if self.distributions['p_x'] == 'bernoulli':
            origin_x = tf.reshape(self.x, [self.batch_size, self.dim_x])
            self.log_lik = -tf.reduce_sum(
                utils.tf_binary_xentropy(origin_x, self.x_recon), 1)

        l2 = tf.add_n([tf.nn.l2_loss(v) for v in tf.trainable_variables()])

        # print("post_z: ", post_z.shape)
        # print("prior_z: ", prior_z.shape)
        # print("log_like: ", self.log_lik.shape)
        self.cost = tf.reduce_mean(post_z - prior_z -
                                   self.log_lik) + self.l2_loss * l2

        ##################
        ''' Evaluation '''
        ##################

        self.z_sample_eval, _, _ = self._generate_zx(self.x,
                                                     phase=pt.Phase.test,
                                                     reuse=True)
        self.x_recon_eval, _ = self._generate_xz(self.z_sample_eval,
                                                 phase=pt.Phase.test,
                                                 reuse=True)

        self.eval_log_lik = -tf.reduce_mean(
            tf.reduce_sum(utils.tf_binary_xentropy(self.x, self.x_recon_eval),
                          1))