Draw bootstrap samples of observations or groups of
observations and specify which bootstrap estimator of
prediction error to compute.
Usage
bootSamples(n, R = 1, type = c("0.632", "out-of-bag"),
grouping = NULL)
Arguments
n
an integer giving the number of observations for
which to draw bootstrap samples. This is ignored if
grouping is supplied in order to respect the group
structure of the data in the bootstrap samples.
R
an integer giving the number of bootstrap
samples.
type
a character string specifying a bootstrap
estimator. Possible values are "0.632" (the
default), or "out-of-bag".
grouping
a factor specifying groups of
observations. If supplied, the groups are resampled
rather than individual observations such that all
observations within a group belong either to the
bootstrap sample or the test data.
Value
An object of class "bootSamples" with the
following components:
n
an integer giving the number of observations or
groups.
R
an integer giving the number of bootstrap
samples.
subsets
an integer matrix in which each column
contains the indices of the observations or groups in the
corresponding bootstrap sample.
grouping
a list giving the indices of the
observations belonging to each group. This is only
returned if a grouping factor has been supplied.
References
Efron, B. (1983) Estimating the error rate of a
prediction rule: improvement on cross-validation.
Journal of the American Statistical Association,
78(382), 316--331.