Procedures for computing Smoothing and Interpolating Natural Splines [E1] (Algorithm A480) CACM August, 1974 Lyche, T. Schumaker, L. L. approximation, interpolation, spline, natural spline, spline smoothing 5.13 CA740809 JB January 17, 1978 9:40 AM 2615 5 2615 2615 5 2615 2615 5 2615