R-users E-mail: r-help@r-project.org Hi! R-users.
http://finzi.psych.upenn.edu/R/library/mvpart/html/xpred.rpart.html says: data(car.test.frame) fit <- rpart(Mileage ~ Weight, car.test.frame) xmat <- xpred.rpart(fit) xerr <- (xmat - car.test.frame$Mileage)^2 apply(xerr, 2, sum) # cross-validated error estimate # approx same result as rel. error from printcp(fit) apply(xerr, 2, sum)/var(car.test.frame$Mileage) printcp(fit) I carried out the R object: function () { # library(mvpart) xx1 <- c(1,2,3,4,5,6,7,8,9,10) xx2 <- c(5,2,1,4,3,6,2,8,2,2) xx3 <- c(9,8,3,7,2,3,1,9,1,6) yy <- c(1,8,2,7,4,3,1,2,2,8) data1 <- data.frame(x1=xx1, x2=xx2, x3=xx3, y=yy) set.seed(345) rpart.out1 <- rpart(y~., data=data1) re1 <- rpart.out1$cptable[,"rel error"] print("re1") print(re1) xmat <- xpred.rpart(rpart.out1) xerr <- (xmat - yy)^2 re2 <- apply(xerr, 2, sum)/var(yy) print("re2") print(re2) } The result is: "re1" 1 2 3 1.00000000 0.08891993 0.03258845 "re2" 0.72777002 0.16019126 0.02373425 11.11111 14.32524 13.12762 Apparently, "re1" is not close to "re2". I would like to know why. -- ***** [EMAIL PROTECTED] ***** http://cse.naro.affrc.go.jp/takezawa/intro.html [[alternative HTML version deleted]] ______________________________________________ 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.
