R/nonspecificity.R

In evclust: Evidential Clustering

#' Nonspecificity of the relational representation of a credal partition
#'
#' \code{nonspecificity} the average nonspecificity of a credal partition, as defined 
#' in Denoeux et al (2018).
#'
#' @param P The relation representation of a credal partition as generated by 
#' \code{\link{pairwise_mass}}.
#'
#' @return The mean nonspecificity (i.e, the average nonspecificity of pairwise mass functions in P).
#' 
#' @export
#'
#' @seealso \code{\link{credal_RI}}, \code{\link{pairwise_mass}}
#'
#' @references
#'  T. Denoeux, S. Li and S. Sriboonchitta. Evaluating and Comparing Soft Partitions: an 
#'  Approach Based on Dempster-Shafer Theory. IEEE Transactions on Fuzzy Systems, 
#'  26(3):1231-1244, 2018.
#'
#' @examples
#' ## Butterfly data
#' data(butterfly)
#' clus<-kevclus(butterfly,c=2)
#' P<-pairwise_mass(clus)
#' print(nonspecificity(P))
#' 

nonspecificity<- function(P) NS<- mean(P$Me + (1-P$Me-P$M1-P$M0))