tensorflow_probability/python/distributions/von_mises_fisher.py
def _log_normalization(self):
    """Computes the log-normalizer of the distribution."""
    event_dim = tf.compat.dimension_value(self.event_shape[0])
    if event_dim is None:
      raise ValueError('vMF _log_normalizer currently only supports '
                       'statically known event shape')
    safe_conc = tf.where(self.concentration > 0,
                         self.concentration,
                         tf.ones_like(self.concentration))
    safe_lognorm = ((event_dim / 2 - 1) * tf.math.log(safe_conc) -
                    (event_dim / 2) * np.log(2 * np.pi) -
                    tf.math.log(_bessel_ive(event_dim / 2 - 1, safe_conc)) -
                    tf.abs(safe_conc))
    log_nsphere_surface_area = (
        np.log(2.) + (event_dim / 2) * np.log(np.pi) -
        tf.math.lgamma(tf.cast(event_dim / 2, self.dtype)))
    return tf.where(self.concentration > 0,
                    -safe_lognorm,
                    log_nsphere_surface_area * tf.ones_like(safe_lognorm))
def _log_normalization(self):
    """Computes the log-normalizer of the distribution."""
    event_dim = tf.compat.dimension_value(self.event_shape[0])
    if event_dim is None:
      raise ValueError('vMF _log_normalizer currently only supports '
                       'statically known event shape')
    safe_conc = tf.where(self.concentration > 0,
                         self.concentration,
                         tf.ones_like(self.concentration))
    safe_lognorm = ((event_dim / 2 - 1) * tf.math.log(safe_conc) -
                    (event_dim / 2) * np.log(2 * np.pi) -
                    tf.math.log(_bessel_ive(event_dim / 2 - 1, safe_conc)) -
                    tf.abs(safe_conc))
    log_nsphere_surface_area = (
        np.log(2.) + (event_dim / 2) * np.log(np.pi) -
        tf.math.lgamma(tf.cast(event_dim / 2, self.dtype)))
    return tf.where(self.concentration > 0,
                    -safe_lognorm,
                    log_nsphere_surface_area * tf.ones_like(safe_lognorm))
Computes the log-normalizer of the distribution.