R/delete.neighbor.R

In BayesX: R Utilities Accompanying the Software Package BayesX

delete.neighbor <- function(map, region1, region2) {
  if (!inherits(map, "gra")) 
    stop("Argument 'map' is not an object of class 'gra'!")
  
  # names of districts
  districts <- rownames(map)
  
  # find index of the regions with changes
  ind1 <- which(districts == region1)
  ind2 <- which(districts == region2)
  
  # modify neighborhoopd structure
  map[ind1, ind2] <- map[ind2, ind1] <- 0
  
  # and adjust no. of neighbors
  map[ind1, ind1] <- -sum(map[ind1, -ind1])
  map[ind2, ind2] <- -sum(map[ind2, -ind2])
  
  class(map) <- "gra"
  return(map)
}