[R-sig-Geo] image background for spplot of gridded data

[Agustin Lobo]

and would it possible a similar plot using contourplot() (or
levelplot()) overlaid
on a gmap?

I've tried the equivalent to the
stamen.R function that you refer to:

contourplot(rinvmod2goog,zscaleLog=TRUE,
            at=my.at,colorkey=myColorkey,margin=FALSE,add=TRUE) +
  layer(grid.raster(gmap2,
                    x=lonCenter2, y=latCenter2,
                    width=width2, height=height2,
                    default.units='native'),under=TRUE)

and get no error but just the contour. I've tried with my object in
pseudomercator and "lon-lat" geographic coordinates:
rinvmod2goog <- projectRaster(from=rinvmod2, crs=CRS("+init=epsg:3857"))
rinvmod2lonlat <- projectRaster(from=rinvmod2, crs=CRS("+proj=longlat
+ellps=WGS84 +no_defs"))

both rinvmod2 and and gmap2 display fine independently.

Data:
https://dl.dropboxusercontent.com/u/3180464/rinvmod2.rda
https://dl.dropboxusercontent.com/u/3180464/gmap2.rda
(to be used with load())

Thanks

Agus

On Wed, Nov 20, 2013 at 6:47 PM, Oscar Perpiñan
<oscar.perpinan at gmail.com> wrote:
> Hi,
>
> For the sake of completeness: just a few days ago I received a comment
> to a post about spplot and ggmap
> (http://procomun.wordpress.com/2013/04/24/stamen-maps-with-spplot/).
> There I was using a SpatialPointsDataFrame object. Because of that
> comment I posted another example with SpatialPolygonsDataFrame:
> https://gist.github.com/oscarperpinan/7482848
>
> Best,
>
> Oscar.
> -----------------------------------------------------------------
> Oscar Perpiñán Lamigueiro
> Grupo de Sistemas Fotovoltaicos (IES-UPM)
> Dpto. Ingeniería Eléctrica (ETSIDI-UPM)
> URL: http://oscarperpinan.github.io
> Twitter: @oscarperpinan
>
>
> 2013/11/20 Waichler, Scott R <Scott.Waichler at pnnl.gov>:
>> I was told, among other things, to look for previous messages by Oscar that would explain how to do this.  Here is Oscar's solution that I found to work for the case where you want to plot two rasters that have different extents.  In my case, gmap is a satellite image obtained with RgoogleMaps, and z are the results I want to plot over the background image.  I made the alpha values of z less than 1 so that the background image would show through.
>>
>> library(rasterVis)
>> levelplot(z~x*y) +
>> layer_(grid.raster(gmap, y=latCenter, width=width, height=height, default.units='native'))
>>
>> Scott Waichler
>>
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>
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