说明：  SPLINE is a package of simple routines for setting up and evaluating splines and related functions, whose goal is either to to interpolate given data exactly at a set of points to approximate data over an interval. There are a variety of types of splines available, including least squares polynomials, divided difference polynomials, piecewise polynomials, and various B, Bernstein, beta, Bezier, Hermite and Overhauser splines. Also included are a set of routines that return the local "basis matrix", which allows the evaluation of the spline in terms of local function data.