Question

I have a shape file with two different region with 12 sub region each.I want separate shape file of these 24 sub region from that shape file.I have also tried by using package maptools and rgeos but could not figure it.Any logarithm would be very much appreciated. Thanks.

sharif

Answer 1

You can split your data in a loop based on the unique value in the column of interest and write out the subset data. I am using rgdal in leu of maptools but you could easily change the code to use maptools functions for reading/writing shapefiles.

require(sp)
require(rgdal)

# READ SHAPEFILE
dat <- readOGR("C:/DATA", "dat")

# CREATE VECTOR OF UNIQUE SUBREGION VALUES
y <- unique(dat@data$SUBREGIONS)

# CREATE SHAPEFILE FOR EACH SUBREGION AND WRITE OUT 
  for (i in 1:length(y) ) {
    temp <- dat[dat$SUBREGIONS == y[i], ]   
  writeOGR(temp, dsn=getwd(), y[i], driver="ESRI Shapefile", 
           overwrite_layer=TRUE)
   }