We exhibit efficient algorithms to perform the following task: Given a function $f$ defined on a finite subset $E \subset \mathbb R^n$, compute a $C^m$ function $F$ on $\mathbb R^n$, with a controlled $C^m$ norm, that approximates $f$ on the subset $E$.
"Fitting a $C^m$-Smooth Function to Data II." Rev. Mat. Iberoamericana 25 (1) 49 - 273, March, 2009.