    def __init__(self, x_dim):
        """Initializes a scaler.

        Arguments:
        x_dim (int): The dimensionality of the inputs into the scaler.

        Returns: None.
        """
        self.fitted = False
        with tf.variable_scope("Scaler"):
            self.mu = tf.get_variable(
                name="scaler_mu", shape=[1, x_dim], initializer=tf.constant_initializer(0.0),
                trainable=False
            )
            self.sigma = tf.get_variable(
                name="scaler_std", shape=[1, x_dim], initializer=tf.constant_initializer(1.0),
                trainable=False
            )

        self.cached_mu, self.cached_sigma = np.zeros([0, x_dim]), np.ones([1, x_dim])
Initializes a scaler.

Arguments:
x_dim (int): The dimensionality of the inputs into the scaler.

Returns: None.
mbpo/models/utils.py