code: def smoothstep(edge0, edge1, x):
      
      # Scale, bias and saturate x to 0..1 range
      x = np.clip((x - edge0)/(edge1 - edge0), 0.0, 1.0)
      # Evaluate polynomial
      return x*x*(3 - 2*x)
docs: performs smooth Hermite interpolation
          between 0 and 1 when edge0 < x < edge1.