import tensorflow as tf

            # sigma = tf.layers.dense(layer_a2, self.a_dim, tf.nn.softplus, kernel_regularizer=reg)
            sigma = tf.get_variable(name='pi_sigma', shape=self.a_dim, initializer=tf.constant_initializer(0.5))
            sigma = tf.clip_by_value(sigma, 0.0, 1.0)
            norm_dist = tf.distributions.Normal(loc=mu * self.a_bound, scale=sigma)
