IMA Journal of Numerical Analysis vol:12 issue:2 pages:271-299
Algorithms are presented for fitting a Powell-Sabin spline to a set of scattered data. Both the determination of least-squares and smoothing splines are considered. For the latter we adopt the philosophy of an existing tensor product spline algorithm. The triangulation is determined in an automatic and adaptive way. The algorithm employs a single parameter to control the tradeoff between closeness of fit and smoothness of fit.