code: def walk(self):
          
  
          if self.verbose > 1:
              print_('\t' + self._id + ' Running Walk proposal kernel')
  
          # Mask for values to move
          phi = self.phi
  
          theta = self.walk_theta
  
          u = random(len(phi))
          z = (theta / (1 + theta)) * (theta * u ** 2 + 2 * u - 1)
  
          if self._prime:
              xp, x = self.values
          else:
              x, xp = self.values
  
          if self.verbose > 1:
              print_('\t' + 'Current value = ' + str(x))
  
          x = x + phi * (x - xp) * z
  
          if self.verbose > 1:
              print_('\t' + 'Proposed value = ' + str(x))
  
          self.stochastic.value = x
  
          # Set proposal adjustment factor
          self.hastings_factor = 0.0
docs: Walk proposal kernel