R/density.R

In O1sims/networkR: A package for analysing social and economic networks

#' Density of a network
#'
#' This function calculates the density of a network graph.
#' @param edgeList A dataframe of network data within which sources are in the first column and targets are in the second column.
#' @param nodeList A dataframe within which all nodes and their respective names are listed.
#' @param undirected Is the network graph undirected? TRUE or FALSE.
#' @keywords density
#' @export
#' @examples
#' density()

density <- function(edgeList, nodeList, undirected = TRUE) {
  edges <- unique(edgeList[, ])
  if (undirected) {
    undirectedNet <- rbind(
      edges,
      data.frame(
        sources = edges[, 2],
        targets = edges[, 1]))
    undirectedNet <- unique(undirectedNet[, ])
    density <- nrow(undirectedNet) / (nrow(nodeList) * (nrow(nodeList) - 1))
  } else {
    edges <- unique(edgeList[, ])
    density <- nrow(edges) / (nrow(nodeList) * (nrow(nodeList) - 1))
  }
  return(density)
}