On Wednesday 19 May 2010 15:08, Joris Meys wrote: > Dear all, > > for demonstration purposes I want to display the basis functions used by a > thin plate regression spline in a gamm model. I've been searching the help > files, but I can't really figure out how to get the plots of the basis > functions. Anybody an idea? > > Some toy code : > > require(mgcv) > require(nlme) > > x1 <- 1:1000 > x2 <- runif(1000,10,500) > > fx1 <- -4*sin(x1/50) > fx2 <- -10*(x2)^(1/4) > y <- 60+ fx1 + fx2 + rnorm(1000,0,5) > > test <- gamm(y~s(x1)+s(x2)) > > plot(test$gam) >
## plots basis functions in space of identifiability constraints, set ## absorb.cons=FALSE for original basis functions um <- smoothCon(s(x1),data=data.frame(x1=sort(x1)), knots=NULL,absorb.cons=TRUE) X <- um[[1]]$X plot(sort(x1),X[,1],ylim=range(X),type="l") for (i in 2:ncol(X)) lines(sort(x1),X[,i],col=i) best, Simon > This gives me the conditional estimates, but not the basis functions for > the different splines. I'd like to have the basis functions for s(x1) and > s(x2). > > Cheers > Joris -- > Simon Wood, Mathematical Sciences, University of Bath, Bath, BA2 7AY UK > +44 1225 386603 www.maths.bath.ac.uk/~sw283 ______________________________________________ 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.