If you you use robust fitting (family = "symmetric"), there are (at least) two sets of weights used (and documented in the Help file): tricube weights are used to weight the points by their distances from the current point being estimated; bisquare weights are used in the robust fit to weight by scaled residual size.
-- Bert Gunter Genentech -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Snow Sent: Thursday, January 22, 2009 9:38 AM To: Marcin Kozak; [email protected] Subject: Re: [R] Loess fitting with bisquare The loess function in R uses the tricube weights that are described in my copy of Cleveland, so that may do what you want. If you really want to do the same general idea but with a different weight function, then it is not that hard to write your own function to do the estimating (but I doubt that you will see much improvement over the standard loess function). -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [email protected] 801.408.8111 > -----Original Message----- > From: [email protected] [mailto:r-help-boun...@r- > project.org] On Behalf Of Marcin Kozak > Sent: Thursday, January 22, 2009 10:08 AM > To: [email protected] > Subject: [R] Loess fitting with bisquare > > Hi, > > It seems there is no straightforward way to carry out in R the loess > fitting with bisquare, as given by William Cleveland in his > "Visualizing Data". Am I right? > > Thanks in advance, > Marcin > > -- > "Build up your weaknesses until they become your strong points" -- > Knute Rockne > > ______________________________________________ > [email protected] 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. ______________________________________________ [email protected] 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. ______________________________________________ [email protected] 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.
