Data on Children who have had Corrective Spinal Surgery

Description

The kyphosis data frame has 81 rows and 4 columns. representing data on children who have had corrective spinal surgery

Usage

data(kyphosis)

Format

This data frame contains the following columns:

Kyphosis

a factor with levels absent present indicating if a kyphosis (a type of deformation) was present after the operation.

Age

in months

Number

the number of vertebrae involved

Start

the number of the first (topmost) vertebra operated on.

Source

John M. Chambers and Trevor J. Hastie eds. (1992) Statistical Models in S, Wadsworth and Brooks/Cole, Pacific Grove, CA 1992.

Examples

data(kyphosis)
fit <- rpart(Kyphosis ~ Age + Number + Start, data=kyphosis)
fit2 <- rpart(Kyphosis ~ Age + Number + Start, data=kyphosis,
              parms=list(prior=c(.65,.35), split='information'))
fit3 <- rpart(Kyphosis ~ Age + Number + Start, data=kyphosis,
              control=rpart.control(cp=.05))
par(mfrow=c(1,2))
plot(fit)
text(fit, use.n=TRUE)
plot(fit2)
text(fit2, use.n=TRUE)