R/OTPtransitivity.R

In nemBM: Using Network Evolution Models to Generate Networks with Selected Blockmodel Type

#' Outgoing two-path mechanism
#'
#' @description Calculates the network statistic according to the outgoing two path mechanism.
#' @name OTPtransitivity
#' @param X Binary network; of class \code{matrix}.
#' @param actor A unit (actor; row/column number), which have an opportunity to change a link.
#' @return A vector with the number of paths of length two between the actor and other units.
#' @examples
#' X <- matrix(sample(c(0,1), size = 9**2, replace = TRUE), nrow = 9)
#' OTPtransitivity(X, actor = 2)
#' @author Marjan Cugmas and Aleš Žiberna
#' @references 
#' Cugmas, M., & Žiberna, A. (2022). Approaches to blockmodeling dynamic networks: a Monte Carlo simulation study. Social Networks, in print.
#' @export

OTPtransitivity <- function (X, actor) {
  counts <- NULL
  for (i in 1:nrow(X)) {
    friends <- cbind(X[actor, ], X[, i])
    counts[i] <- sum(rowSums(friends) == 2)
  }
  if (sum(counts) != 0) counts <- counts/sum(counts)
  return(counts)
}