code: def logpost(self, theta, t=None):
          
          return self.prior.logpdf(theta) + self.loglik(theta, t)
docs: Posterior log-density at given parameter values. 
  
          Parameters
          ----------
          theta: dict-like
              theta['par'] is a ndarray containing the N values for parameter par
          t: int 
              time (if set to None, the full posterior is returned)
  
          Returns
          -------
          l: float numpy.ndarray
              the N log-likelihood values