hbootindex function

Hierarchical bootstrap indices

Generates hierarchical bootstrap indices.

hbootindex(groups, strata, B = 199)

Arguments

• groups: group membership vector.
• strata: strata, optional.
• B: number of bootstrap iterations.

Details

Resampling with replacement with weights proportional to the number of observations in each of the group level (unique values in groups).

Values of groups within levels (unique values) of strata

are resampled independently of other strata levels.

Returns

A matrix with bootstrapped indices, number of columns is B + 1. The column is a resample without replacement (random subsets can be selected without further reshuffling). Other elements contain indices according to rules described in Details section (these also randomly reshuffled).

Author(s)

Peter Solymos

Examples

## equal group sizes
groups <- rep(1:4, each=5)
strata <- rep(1:2, each=10)
hbootindex(groups, strata, 3)

## unequal group sizes
groups <- groups[-c(5,9,10,11)]
strata <- strata[-c(5,9,10,11)]
hbootindex(groups, strata, 3)