Hi I would like to fit a function H = F(x,y,z) but I do not know the analytical expression of H, is there a way to get the best 3d polynomial (in x,y,z) which fits H e.g H<-seq(2,200,len=50) x<-seq(1,50,len=50) y<-seq(50,300,len=50) x<-seq(30,80,len=50) so it is a sort of fitting a 4 dimensional surface to a regular grid any suggestions are very much appreciated best regards Karim
Karim -
try function gam() in package mgcv.
library("mgcv")
help("gam")
- tom blackwell - u michigan medical school - ann arbor -
On Mon, 6 Oct 2003, Karim Elsawy wrote:
> I would like to fit a function H = F(x,y,z) but I do not know the
> analytical expression
> of H, is there a way to get the best 3d polynomial (in x,y,z) which fits
> H
> e.g
> H<-seq(2,200,len=50)
> x<-seq(1,50,len=50)
> y<-seq(50,300,len=50)
> x<-seq(30,80,len=50)
>
> so it is a sort of fitting a 4 dimensional surface to a regular grid
>
> any suggestions are very much appreciated
> best regards
> Karim
Or even mars() in the mda package... Andy> From: Thomas W Blackwell [mailto:tblackw at umich.edu] > > Karim - > > try function gam() in package mgcv. > > library("mgcv") > help("gam") > > - tom blackwell - u michigan medical school - ann arbor - > > On Mon, 6 Oct 2003, Karim Elsawy wrote: > > > I would like to fit a function H = F(x,y,z) but I do not know the > > analytical expression of H, is there a way to get the best 3d > > polynomial (in x,y,z) which fits H > > e.g > > H<-seq(2,200,len=50) > > x<-seq(1,50,len=50) > > y<-seq(50,300,len=50) > > x<-seq(30,80,len=50) > > > > so it is a sort of fitting a 4 dimensional surface to a > regular grid > > > > any suggestions are very much appreciated > > best regards > > Karim > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo> /r-help >