R/bwps.R

In geo: Draw and Annotate Maps, Especially Charts of the North Atlantic

#' Open a postscript device with the color scheme given by geoplotbwpalette.
#' (black and white)
#' 
#' The function starts a postscript device and the arguments are the same as
#' the arguments to postscript (height, width, file, bg etc) . The color scheme
#' is 1 black, 2-155 white to black in even steps.
#' 
#' <!--explain details here-->
#' 
#' @param ... The arguments to postscript are optional. See help postscript.
#' @return No value returned.
#' @section Side Effects: A graphics device is opened (often a file).  It must
#' be closed again by dev.off()
#' @seealso postscript, geoplotbwpalette,litir
#' @keywords devices
#' @examples
#' 
#' \dontrun{
#' bwps(file="map1.ps",height=6,width=5) 
#' geoplot(xlim=c(-28,-10),ylim=c(64,69))
#' geosymbols(data,z=data$value,circles=0.2,sqrt=T)
#' geopolygon(island,col="white")# paint white over the symbols 
#' geolines(island) # that are inside the country.  (island) 
#' dev.off() 
#' 
#' # same example in a different way.  
#' bwps(file="map1.ps",height=6,width=5,bg="white") 
#' geoplot(xlim=c(-28,-10),ylim=c(64,69))
#' geosymbols(data,z=data$value,circles=0.2,sqrt=T)
#' geopolygon(island,col=0)#col 0 is now white
#' geolines(island) # was transparent earlier
#' dev.off() }
#' 
#' @export bwps
bwps <-
function(...){
  postscript(...) 
  geoplotbwpalette()
}