R/write.gra.R

In BayesX: R Utilities Accompanying the Software Package BayesX

write.gra <- function(map, file, replace = FALSE) {
  if (!inherits(map, "gra")) 
    stop("Argument 'map' is not an object of class 'gra'!")
  
  ## check whether the file exists
  if (replace & file.exists(file)) 
    test <- file.remove(file)
  if (!replace & file.exists(file)) 
    stop("Specified file already exists!")
  
  ## names of districts
  districts <- as.integer(rownames(map))
  
  ## no. of regions
  S <- length(districts)
  write(S, file)
  
  ## loop over the regions
  for (i in 1:S) {
    ## write name of the district
    write(districts[i], file, append = TRUE)
    ## write no. of neighbors
    write(map[i, i], file, append = TRUE)
    
    ## derive and write neighbors
    ind <- which(map[i, ] == -1) - 1
    write(ind, file, ncolumns = length(ind), append = TRUE)
  }
  
  return(invisible())
}