% HECUB   : Determination of a Cubic Hermite Spline Interpolant      [f]% [c,d] = hecub(x,y,b);function [c,d]=hecub(x,y,b)
n = length(x);
if n<= 2,  error('n moet groter zijn dan 2');endfor k=1:n-1,  k1 = k+1;  h=x(k1)-x(k);  dydx = (y(k1)-y(k))/h;  c(k)=(3.0 * dydx - 2.0 * b(k)-b(k1))/h;  d(k) = (-2.0 * dydx + b(k)+b(k1))/(h*h);end