code: def logdet(self):
          
          from numpy.linalg import slogdet
  
          K = self.value()
  
          sign, logdet = slogdet(K)
          if sign != 1.0:
              msg = "The estimated determinant of K is not positive: "
              msg += f" ({sign}, {logdet})."
              raise RuntimeError(msg)
  
          return logdet
docs: Log of ｜K｜.
  
          Returns
          -------
          float
              Log-determinant of K.