R/vector_to_raster.R

In juoe/spatialtools: Collection of functions for doing spatial stuff.

#' Rasterize vector files via gdal_rasterize using gdalUtils.
#'
#' @param x sf or Spatial object.
#' @param y Raster Object.
#' @param field Column name of x containing values used for rasterization.
#' @param burn Value to "burn" into raster (only used when "field" is not set).
#' @param filename Optional filename for writing output. If no filename is supplied, a temporary file will be created.
#' @return Rasterized input.
#' @export

vector_to_raster <- function(x, y, field = NULL, burn = 1, filename = NULL) {

  if (is.null(filename)) {
    filename <- tempfile(fileext='.tif')
  }

  if(isTRUE(attr(class(x), "package") == "sp")) {
    x <- st_as_sf(x)
  }

  y <- raster::mask(y, is.na(y), inverse = TRUE, updatevalue = NA)
  raster::writeRaster(y, filename, overwrite = TRUE)

  tmp_shape <- tempfile(fileext='.shp')
  sf::st_write(x, tmp_shape, delete_dsn = TRUE)

  if(is.null(field)) {
    rast_args <- list(tmp_shape, filename, burn = 1, output_Raster = TRUE)
  } else {
    rast_args <- list(tmp_shape, filename, a = field, output_Raster = TRUE)
  }

  do.call(gdal_rasterize, rast_args)
  out <- raster(filename)

  return(out)

}