R/get.neighbor.R

In BayesX: R Utilities Accompanying the Software Package BayesX

get.neighbor <- function(map, regions) {
  if (!inherits(map, "gra")) 
    stop("Argument 'map' is not an object of class 'gra'!")
  
  districts <- rownames(map)
  
  neighbors <- list(length = length(regions))
  for (i in 1:length(regions)) {
    ind <- which(districts == regions[i])
    neighbors[[i]] <- districts[map[ind, ] == -1]
  }
  
  names(neighbors) <- regions
  return(neighbors)
}