SPLINS and SMOOTH: two FORTRAN smoothing routines

Abstract

Two FORTRAN subroutines are presented that determine interpolating functions for experimental data. The first produces a spline where the smoothness of the function and the degree to which it fits the data is determined by the user. The second allows subdivision of the data, with individual polynomials being used to approximate the data on each interval and the polynomials are constrained to be piecewise continuous along with their first derivatives. An option to make the second derivative continuous is also available.