I don't think that there are any multivariate equivalents to aproxfun and spline fun, but you could create your own function that takes whatever inputs you want and uses predict.loess with the prefit loess object to create predictions.
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 From: Christian Miner [mailto:christian.mi...@gmail.com] Sent: Monday, November 23, 2009 2:13 PM To: Greg Snow Cc: Thomas S. Dye; r-help@r-project.org Subject: Re: [R] Loess Fit What if you wanted to do this with multiple x's, multivariate, rather than just 1 x variable? On Mon, Nov 23, 2009 at 1:09 PM, Greg Snow <greg.s...@imail.org<mailto:greg.s...@imail.org>> wrote: approxfun returns a function, give this function an x-value and it will give you the prediction (linear interpolation from the points that you gave to approxfun). The splinefun function also returns a function, but it gives a spline interpolation rather than a linear one. -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org<mailto:greg.s...@imail.org> 801.408.8111 From: Christian Miner [mailto:christian.mi...@gmail.com<mailto:christian.mi...@gmail.com>] Sent: Monday, November 23, 2009 2:05 PM To: Greg Snow Cc: Thomas S. Dye; r-help@r-project.org<mailto:r-help@r-project.org> Subject: Re: [R] Loess Fit Thanks, I'll try that. What is the output of approxfun? On Mon, Nov 23, 2009 at 1:03 PM, Greg Snow <greg.s...@imail.org<mailto:greg.s...@imail.org>> wrote: If the client is always right, then what do they need us for? If you need a function to reproducibly generate predictions, then use loess to generate a set of predictions for a reasonably dense set of x-values, then use approxfun or splinefun to create a function to interpolate for you. Then this function can give the predictions for various x values. -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org<mailto:greg.s...@imail.org> 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org> > [mailto:r-help-boun...@r-<mailto:r-help-boun...@r-> > project.org<http://project.org>] On Behalf Of Thomas S. Dye > Sent: Monday, November 23, 2009 1:39 PM > To: Christian Miner > Cc: r-help@r-project.org<mailto:r-help@r-project.org> > Subject: Re: [R] Loess Fit > > Thanks Christian. The client is always right ... > > Tom > > On Nov 23, 2009, at 10:32 AM, Christian Miner wrote: > > > sorry, I don't. I have data that I can estimate, but my client wants > > to "What if..." 20 separate scenarios, and that requires a function. > > > > On Mon, Nov 23, 2009 at 12:22 PM, Thomas S. Dye > > <t...@tsdye.com<mailto:t...@tsdye.com>> > wrote: > > Hi Christian, > > > > Do you have a reference to a publication where this has been done? > > > > All the best, > > Tom > > > > On Nov 23, 2009, at 10:15 AM, Christian Miner wrote: > > > >> it's a tricky maneuver. When I finish the fit, the predict function > >> will give me the values, and I can smooth this out so it looks like > >> a nice non-linear equation. The last thing I need to do is find the > >> equation, knowing I know have the x and y values, as they will > >> relate to each other in a non-linear fashion. > >> > >> Matlab can do this, but I'd rather not go into that realm. > >> > >> On Mon, Nov 23, 2009 at 12:11 PM, Thomas S. Dye > >> <t...@tsdye.com<mailto:t...@tsdye.com>> > >> wrote: > >> Hi Christian, > >> > >> I haven't seen an equation associated with a loess fit before. Do > >> you have a reference to one of these? > >> > >> All the best, > >> Tom > >> > >> > >> On Nov 23, 2009, at 9:03 AM, Christian Miner wrote: > >> > >> I'm working on Loess fit models using R, once I have the fit > >> accomplished, > >> I'm looking to back-out the equation of the fitted non-linear curve, > >> wondering if there is a way to determine this equation in R? I've > >> been > >> looking but can't find any literature. For me, the graph of the > >> function is > >> great, but without the equation of the graph, I'm kinda dead in the > >> water. > >> > >> Christian Miner > >> 503-866-6977 > >> > >> [[alternative HTML version deleted]] > >> > >> ______________________________________________ > >> R-help@r-project.org<mailto:R-help@r-project.org> mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-help > >> PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > >> and provide commented, minimal, self-contained, reproducible code. > >> > >> > >> > >> > >> -- > >> Christian Miner > >> 503-866-6977 > >> > > > > > > > > > > -- > > Christian Miner > > 503-866-6977 > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org<mailto:R-help@r-project.org> mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code. -- Christian Miner 503-866-6977 -- Christian Miner 503-866-6977 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
