clip.rpart {maptree}R Documentation

Prunes an Rpart Classification or Regression Tree

Description

Reduces a prediction tree produced by rpart to a smaller tree by specifying either a cost-complexity parameter, or a number of nodes to which to prune.

Usage

  clip.rpart (tree, cp=NULL, best=NULL)

Arguments

tree object of class rpart.
cp cost-complexity parameter.
best number of nodes to which to prune.


If both cp and best are not NULL, then cp is used.

Details

A minor enhancement of the existing prune.rpart to incorporate the parameter best as it is used in prune.tree. See example.

Value

Pruned tree object of class rpart.

Author(s)

Denis White, white.denis@epa.gov

See Also

prune.tree, rpart, prune.rpart

Examples

  library (rpart)
  data (oregon.env.vars, oregon.border, oregon.grid)

  draw.tree (clip.rpart (rpart (oregon.env.vars), best=7), 
    nodeinfo=TRUE, units="species", cases="cells", digits=0)

  group <- group.tree (clip.rpart (rpart (oregon.env.vars), best=7))
  names(group) <- row.names(oregon.env.vars)
  map.groups (oregon.grid, group)
  lines (oregon.border)
  map.key (0.05, 0.65, labels=as.character(seq(6)), 
    size=1, new=FALSE, sep=0.5, pch=19, head="node")

[Package maptree version 1.4-5 Index]