code: def nhill_i(self,x,threshold=0.1,power=2):
          
          x_pow = np.power(x,power)
          threshold_pow = np.power(threshold,power)
          return threshold_pow / (x_pow + threshold_pow) * (1 - x_pow)
docs: Normalized inhibiting hill function.
  
              Is equivalent to 1-nhill_a(self,x,power,threshold).