Algorithm 574: Shape-Preserving Osculatory Quadratic Splines [E1, E2]

This algorithm is a FORTRAN implementation for the procedure developed in Let n data points {(x,, y,)} n.1 and n first derivatives {rn,),"-1 at these data points be given, with x, <_-X,+l, 1 __ i __. n -1. The algorithm constructs a smooth osculatory quadratic spline S, which satisfies (1) S(x,) = y,, 1 <_ i <_ n;