[R-sig-Geo] drawing order in spplot

[Edzer J. Pebesma]

Duncan Golicher wrote:

>Many thanks to everyone involved in putting together the excelent sp 
>package. I have just used for teaching a brief intro to applied geostats 
>with gstat. Students found life much easier than a year ago when I had 
>to try to explain a less structured approach to the data.
>A simple question arose after the class. According to the spplot 
>documentation "for grids and polygons sp.layout is drawn afterwards (so 
>the item will not be overdrawn by the grid and/or polygon)".
>So in this example we expected a DEM to be drawn first, then municipal 
>boundaries.
>
> > class(municipios)
>[1] "SpatialPolygonsDataFrame"
> > class(chisgrid)
>[1] "SpatialPixelsDataFrame"
>
>municips <- list("sp.polygons", municipios)
>spplot(chisgrid["dem"],sp.layout=municips)
>
>The municipal boundaries are drawn first then overdrawn by the DEM, 
>which was not what we expected or wanted. I couldn't find how to avoid 
>this, apart from the simple solution of ..
>
>image(chisgrid,col=terrain.colors(20))
>plot(municipios,add=T)
>
>instead of spplot.The figures on  http://r-spatial.sourceforge.net all 
>appear to have the grid drawn first. Is there a way to reverse this?
>
>Duncan
>
>  
>
the sp.layout argument accepts a list item, first=TRUE or first=FALSE,
telling whether to
first or to last plot this item; you could try to use that.

I'll review whether the current setup is logical, or not.
--
Edzer