Hi, I've written a logistic function using nls and I'd like to do cross validation for this. Is there a package for that? Below is an example of my data and the function. N terms are presence/absence data and the response is succesful/failed data. y1<-sample(0:1,100,replace=T) N1<-sample(0:1,100,replace=T) N2<-sample(0:1,100,replace=T) N3<-sample(0:1,100,replace=T) N4<-sample(0:1,100,replace=T) Sw<- function(y1, N1,N2,N3,N4) { SA <- nls(y1~exp(c+(a1*N1)+(a2*N2)+(a3*N3)+(a4*N4) )/ (1+exp(c+(a1*N1)+(a2*N2)+(a3*N3)+(a4*N4))) ,start=list(a1=-0.2,a2=-0.2,a3=-0.2,a4=-0.2,c=0.2)) SA } model<- Sw(y1, N1,N2,N3,N4) summary(model) Thanks for any help! /Anna -- View this message in context: http://r.789695.n4.nabble.com/Cross-validation-for-nls-function-tp4638630.html Sent from the R help mailing list archive at Nabble.com.