I have forgotten to list the definition of pp. Here it is: pp <- function(x,a) {ifelse(x>a, x-a, 0)} ______________________________________
Dear list, when I execute library(mda) x1 <- rnorm(100000,mean=1,sd=.12) x2 <- rnorm(100000,mean=.6,sd=.12) y <- pp(x1,1)+pp(x1,1)*pp(x2,.6)+.12*rnorm(length(x1)) mymars <- mars(cbind(x1,x2),y,degree=2) mymars$cuts mymars$factor I get what I expected. Instead, when I execute x1 <- rnorm(100000,mean=1,sd=.12) x2 <- rnorm(100000,mean=.6,sd=.12) x3 <- rnorm(100000,mean=.2,sd=.12) y <- pp(x1,1)+pp(x2,.6)+pp(x3,.2)+pp(x1,1)*pp(x2,.6)+pp(x1,1)*pp(x3,.2)+pp(x2,.6) *pp(x3,.2)+pp(x1,1)*pp(x2,.6)*pp(x3,.2)+.12*rnorm(length(x1)) mymars <- mars(cbind(x1,x2,x3),y,degree=3,prune=FALSE) mymars$cuts mymars$factor or x1 <- rnorm(100000,mean=1,sd=.12) x2 <- rnorm(100000,mean=.6,sd=.12) x3 <- rnorm(100000,mean=.2,sd=.12) y <- pp(x1,1)*pp(x2,.6)*pp(x3,.2)+.12*rnorm(length(x1)) mymars <- mars(cbind(x1,x2,x3),y,degree=3,prune=FALSE) mymars$cuts mymars$factor I do not get the term of interaction degree 3. What am I thinking wrong? Thank you Jordi -------------------------------------------------------------------------------- The information contained herein is confidential and is inte...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html