R/dominance.R

In diversityArch: Computes Diversity Indices for Archaeological Data

#' @title Dominance index
#'
#' @description Modification of the Simpson's dominance index to be restricted between 0 and 1.
#'
#' @param x Vector of dimension S (number of species) with the number of individuals observed in each species, or the distribution frequencies of species. NA values are allowed.
#'
#' @return Dominance index (Modified Simpson's dominance index).
#'
#' @seealso \link{simpson_D}
#'
#' @references
#' Arnaud Barat, Andreu Sansó, Maite Arilla-Osuna, Ruth Blasco, Iñaki Pérez-Fernández, Gabriel Cifuentes-Alcobenda, Rubén Llorente, Daniel Vivar-Ríos, Ella Assaf, Ran Barkai, Avi Gopher, & Jordi Rosell-Ardèvol (2026) <doi:10.1007/s10816-026-09802-3>.
#'
#' @examples
#' data(Qesem_s)
#' dominance(Qesem_s$HU)
#'
#' @export
dominance <- function(x){
  x <- check_x(x)
  S <- length(x)
  return((S*simpson_D(x)-1)/(S-1))
}