kyphosis {rpart} | R Documentation

## 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

    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

    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)

[Package rpart version 3.1-55 Index]