If you really want interpolation, should you be using spline() rather than smooth.spline()? The later is for smoothing data observed with noise, not for interpolation.
Andy > From: W. C. Thacker > > Dear R listers, > > When using smooth.spline to interpolate data, results are generally > good. However, some cases produce totally unreasonable results. > > The data are values of pressure, temperature, and salinity from a > probe that is lowered into the ocean, and the objective is to > interpolate temperature and salinity to specified pressures. While > smooth.spline provides excellent values at the observed pressures, > there are cases when the values at the desired pressures are > unusable. A dataframe with four such profiles, indicated by values of > id, is attached. My target values for pressure are seq(25,1600,25), > but 1:500 is also interesting. > > Setting all.knots = TRUE helps, but it would be nice to be able to do > better. > > Any suggestions? > > Thanks, > > Carlisle > > > version > _ > platform sparc-sun-solaris2.9 > arch sparc > os solaris2.9 > system sparc, solaris2.9 > status > major 1 > minor 8.0 > year 2003 > month 10 > day 08 > language R > > > -- > > William Carlisle Thacker > > Atlantic Oceanographic and Meteorological Laboratory > 4301 Rickenbacker Causeway, Miami, Florida 33149 USA > Office: (305) 361-4323 Fax: (305) 361-4392 > > "Too many have dispensed with generosity > in order to practice charity." Albert Camus > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > ------------------------------------------------------------------------------ Notice: This e-mail message, together with any attachments,...{{dropped}} ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
