JoshOBrien

##' Rasterize \code{Spatial*} objects using gdal_rasterize.
##'
##' For a 1000-by-1000 raster, \code{gRasterize} is more than 6 times
##' faster than \code{raster::rasterize}. For a 2000-by-2000 raster,
##' it is almost 12 times faster (6 seconds vs. 70 seconds on my
##' Windows laptop).
##'
##' I've modeled \code{gRasterize} arguments and behavior on that of
##' \code{\link[raster]{rasterize}}. Like\code{rasterize},it takes a
##' \code{filename=} argument which defaults to \code{""} in which

JoshOBrien

polygonizer <- function(x, outshape=NULL, gdalformat = 'ESRI Shapefile', 
                        pypath=NULL, readpoly=TRUE, quietish=TRUE) {
  # x: an R Raster layer, or the file path to a raster file recognised by GDAL
  # outshape: the path to the output shapefile (if NULL, a temporary file will be created)
  # gdalformat: the desired OGR vector format
  # pypath: the path to gdal_polygonize.py (if NULL, an attempt will be made to determine the location
  # readpoly: should the polygon shapefile be read back into R, and returned by this function? (logical)
  # quietish: should (some) messages be suppressed? (logical)
  if (isTRUE(readpoly)) require(rgdal)
  if (is.null(pypath)) {