code: def get_fmin(self):
          
          ps = self.model.param_array.copy()
          fmins = []
          for s in self.hmc_samples:
              if self.model._fixes_ is None:
                  self.model[:] = s
              else:
                  self.model[self.model._fixes_] = s
              self.model._trigger_params_changed()
              fmins.append(self.model.predict(self.model.X)[0].min())
          self.model.param_array[:] = ps
          self.model._trigger_params_changed()
  
          return fmins
docs: Returns the location where the posterior mean is takes its minimal value.