R/lineup_prop_tab.R

In tmnaylor/r4lineups: Statistical Inference on Lineup Fairness

#'Lineup proportion
#'
#'Computes the proportion of mock witnesses identifying a particular lineup member
#'@param lineup_table A table of lineup choices
#'@param target_pos A scalar, representing target position in lineup. Must be declared by user
#'@return Returns a proportion indicating the frequency with which a lineup
#'        member was selected
#'@references Wells, G. L.,Leippe, M. R., & Ostrom, T. M. (1979). Guidelines for
#'            empirically assessing the fairness of a lineup. \emph{Law and Human Behavior,
#'            3}(4), 285-293.
#'@examples
#'#Data:
#'lineup_vec <- round(runif(100, 1))
#'lineup_table <- table(lineup_vec)
#'
#'#Call:
#'lineup_prop_tab(lineup_table, 3)
#'lineup_prop_tab(table(lineup_vec), 2)
#'
#'@export

lineup_prop_tab <- function(lineup_table, target_pos){
    lineup_table[target_pos]/sum(lineup_table)
}