code: def _c0(self):
          "the logarithm of normalizing constant in pdf"
          h_df = self.df / 2
          p, S = self._p, self.S
  
          return h_df * (logdet(S) + p * logtwo) + lpgamma(p, h_dff _c0(self):
          "the logarithm of normalizing constant in pdf"
          h_df = self.df / 2
          p, S = self._p, self.S
  
          return h_df * (logdet(S) + p * logtwo) + lpgamma(p, h_df)
docs: the logarithm of normalizing constant in pdf