tree.control {tree}R Documentation

Select Parameters for Tree

Description

The produces default values of mincut and minsize, and ensures that mincut is at least half minsize.

Usage

tree.control(nobs, mincut = 5, minsize = 10, mindev = 0.01)

Arguments

nobs The number of observations in the training set.
mincut The minimum number of observations to include in either child node. This is a weighted quantity; the observational weights are used to compute the `number'. The default is 5.
minsize The smallest allowed node size: a weighted quantity. The default is 10.
mindev The within-node deviance must be at least this times that of the root node for the node to be split.

Details

To produce a tree that perfectly fits the data, set mindev = -1 and minsize = 2.

Value

A list:

mincut The maximum of the input or default mincut and 1
minsize The maximum of the input or default minsize and 2.
nmax A estimate of the maximum number of nodes that might be grown.
nobs The input nobs.

Note

The intepretation of mindev given here is that of Chambers and Hastie (1992, p. 415), and apparently not what is actually implemented in S. It seems S uses an absolute bound.

Author(s)

B. D. Ripley

See Also

tree