Since I'm getting no joy looking for an R implementation of the matlab function csaps, can anybody advise me on porting csaps from Octave? There is an octave implementation of csaps here: http://octave.svn.sourceforge.net/viewvc/octave/trunk/octave-forge/nonfree/spline-gsvspl/inst/csaps.m This function calls external C function gcvspl located here: http://octave.svn.sourceforge.net/viewvc/octave/trunk/octave-forge/nonfree/spline-gsvspl/src/gcvspl.cc Any C gurus out there care to opine on how hard this would be to port to an external C function that R could call. I need to be able to repeat results from csaps as part of a review and don't have access to Matlab (or inclination to install and learn Octave). Or, back to the original query, is there a way to mimic csaps in R? In particular I need to be able to repeat an analysis with the the same smoothing parameter (p) from csaps. Please help! ::DrC