R: PostScript Presentation Plot of an Rpart Object

post.rpart {rpart}

R Documentation

PostScript Presentation Plot of an Rpart Object

Description

Generates a PostScript presentation plot of an rpart object.

Usage

post(tree, ...)

## S3 method for class 'rpart'
post(tree, title., 
     filename = paste(deparse(substitute(tree)), ".ps", sep = ""), 
     digits = getOption("digits") - 3, pretty = TRUE,
     use.n = TRUE, horizontal = TRUE, ...)

Arguments

`tree`	fitted model object of class `rpart`. This is assumed to be the result of some function that produces an object with the same named components as that returned by the `rpart` function.
`title.`	a title which appears at the top of the plot. By default, the name of the `rpart` endpoint is printed out.
`filename`	ASCII file to contain the output. By default, the name of the file is the name of the object given by `rpart` (with the suffix `.ps` added). If `filename = ""`, the plot appears on the current graphical device.
`digits`	number of significant digits to include in numerical data.
`pretty`	an integer denoting the extent to which factor levels will be abbreviated in the character strings defining the splits; (0) signifies no abbreviation of levels. A `NULL` signifies using elements of letters to represent the different factor levels. The default (`TRUE`) indicates the maximum possible abbreviation.
`use.n`	Logical. If `TRUE` (default), adds to label (\#events level1/ \#events level2/etc. for method `class`, `n` for method `anova`, and \#events/n for methods `poisson` and `exp`).
`horizontal`	Logical. If `TRUE` (default), plot is horizontal. If `FALSE`, plot appears as landscape.
`...`	other arguments to the `postscript` function.

Details

The plot created uses the functions plot.rpart and text.rpart (with the fancy option). The settings were chosen because they looked good to us, but other options may be better, depending on the rpart object. Users are encouraged to write their own function containing favorite options.

Side Effects

a plot of rpart is created using the postscript driver, or the current device if filename = "".

Examples

z.auto <- rpart(Mileage ~ Weight, car.test.frame)
post(z.auto, file = "")   # display tree on active device
   # now construct postscript version on file "pretty.ps"
   # with no title
post(z.auto, file = "pretty.ps", title = " ")
z.hp <- rpart(Mileage ~ Weight + HP, car.test.frame)
post(z.hp)

[Package rpart version 3.1-54 Index]