Hierarchical bootstrap indices
hbootindex.RdGenerates hierarchical bootstrap indices.
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.
Value
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).
Examples
## equal group sizes
groups <- rep(1:4, each=5)
strata <- rep(1:2, each=10)
hbootindex(groups, strata, 3)
#> [,1] [,2] [,3] [,4]
#> [1,] 1 13 6 14
#> [2,] 19 18 16 18
#> [3,] 18 4 11 17
#> [4,] 5 13 4 19
#> [5,] 6 18 20 9
#> [6,] 11 4 1 10
#> [7,] 17 6 18 10
#> [8,] 16 9 18 15
#> [9,] 4 9 1 5
#> [10,] 12 19 15 15
#> [11,] 13 13 14 10
#> [12,] 20 14 4 16
#> [13,] 10 1 2 7
#> [14,] 2 3 7 10
#> [15,] 14 4 1 17
#> [16,] 7 17 18 9
#> [17,] 9 4 18 19
#> [18,] 8 18 6 16
#> [19,] 3 13 8 2
#> [20,] 15 6 19 1
## unequal group sizes
groups <- groups[-c(5,9,10,11)]
strata <- strata[-c(5,9,10,11)]
hbootindex(groups, strata, 3)
#> [,1] [,2] [,3] [,4]
#> [1,] 16 3 6 16
#> [2,] 3 3 7 1
#> [3,] 5 4 9 16
#> [4,] 2 4 3 2
#> [5,] 9 7 14 6
#> [6,] 14 15 15 1
#> [7,] 13 1 12 9
#> [8,] 7 14 8 12
#> [9,] 1 10 16 2
#> [10,] 11 12 8 5
#> [11,] 10 10 4 11
#> [12,] 4 14 2 10
#> [13,] 12 9 7 6
#> [14,] 6 4 16 13
#> [15,] 15 9 4 12
#> [16,] 8 16 15 11