code: def hum1_wei(x,y,n=24):
      t = y-1.0j*x
      cerf=1/sqrt(pi)*t/(0.5+t**2)
      
      mask = abs(x)+y<15.0
      if any(mask):
          w24 = weideman(x[mask],y[mask],n)
          place(cerf,mask,w24)
      return cerf.real,cerf.imag
docs: z = x+1j*y
      cerf = 1j*z/sqrt(pi)/(z**2-0.5)