Invert group-index assignment into per-group entry lists.

For each non-zero group in group_indices, returns the integer positions that belong to it. Entries with index 0 are omitted.

Usage

collect_group_members(group_indices)

Arguments

group_indices

Integer vector (or coercible).

Value

A list of integer vectors. Length equals max(group_indices).

See also

compact_groups(), group_names()

Examples

collect_group_members(c(1L, 2L, 1L, 0L, 2L))
#> [[1]]
#> [1] 1 3
#> 
#> [[2]]
#> [1] 2 5
#> 
# list(c(1, 3), c(2, 5))