R version 2.15.0 (2012-03-30) Copyright (C) 2012 The R Foundation for Statistical Computing ISBN 3-900051-07-0 Platform: x86_64-unknown-linux-gnu (64-bit) R is free software and comes with ABSOLUTELY NO WARRANTY. You are welcome to redistribute it under certain conditions. Type 'license()' or 'licence()' for distribution details. R is a collaborative project with many contributors. Type 'contributors()' for more information and 'citation()' on how to cite R or R packages in publications. Type 'demo()' for some demos, 'help()' for on-line help, or 'help.start()' for an HTML browser interface to help. Type 'q()' to quit R. > library(rpart) > require(survival) Loading required package: survival Loading required package: splines > aeq <- function(x,y, ...) all.equal(as.vector(x), as.vector(y), ...) > > # > # 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 ? [1] TRUE > aeq(temp1[indx1,3], temp2[indx2,3]*(1+ 1:7/10)) #scaled importance [1] TRUE > > > > proc.time() user system elapsed 0.288 0.067 0.407