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.