Convert a key vector to a list of question indices by dimension

Takes a scoring key that maps each question to a dimension and returns a list where each element contains the indices of questions belonging to that dimension.

Usage

questions_by_keys(key)

Arguments

key

Integer vector. Each element indicates which dimension the corresponding question belongs to. Values must be consecutive integers starting from 1 up to the number of dimensions.

Value

A named list of length max(key), where element i contains the integer indices of all questions assigned to dimension i.

Examples

key<-c(1,2,3,4,5,1,2,3,4,5)
questions_by_keys(key)
#> [[1]]
#> [1] 1 6
#> 
#> [[2]]
#> [1] 2 7
#> 
#> [[3]]
#> [1] 3 8
#> 
#> [[4]]
#> [1] 4 9
#> 
#> [[5]]
#> [1]  5 10
#>