library(rpart) require(survival) aeq <- function(x,y, ...) all.equal(as.vector(x), as.vector(y), ...) set.seed(10) # # Check out using costs # fit1 <- rpart(Surv(time, status) ~ age + sex + ph.ecog + ph.karno + pat.karno + meal.cal + wt.loss, data=lung, maxdepth=1, maxcompete=6, xval=0) fit2 <- rpart(Surv(time, status) ~ age + sex + ph.ecog + ph.karno + pat.karno + meal.cal + wt.loss, data=lung, maxdepth=1, maxcompete=6, xval=0, cost=(1+ 1:7/10)) temp1 <- fit1$splits[1:7,] temp2 <- fit2$splits[1:7,] temp3 <- c('age', 'sex', 'ph.ecog', 'ph.karno', 'pat.karno', 'meal.cal', 'wt.loss') indx1 <- match(temp3, dimnames(temp1)[[1]]) indx2 <- match(temp3, dimnames(temp2)[[1]]) aeq(temp1[indx1,1], temp2[indx2,1]) #same n's ? aeq(temp1[indx1,3], temp2[indx2,3]*(1+ 1:7/10)) #scaled importance