[R-sig-Geo] Error levelplot+ layer(sp.polygons() +

[Byman]

Dear Oscar

Great! Many thanks, your answer helped resolve my problem. Actually I 
didnt realise that ggplot was contributing to my problem.
I just did not attach ggplot2 library, that was it. No error.

Best regards

Byman

On 25.02.2012 12:19, Oscar Perpiñán Lamigueiro wrote:
> Byman<bymanh at gmail.com>  writes:
>
>> Could anyone please help me.
>> I am plotting raster object (tasc) with 4 seasons: ("DJF","MAM", "JJA",
>> "SON") as layers. I get this raster from an Netcdf file. I would like to
>> add (overlay) the country polygons (afrc) on top of these 4 plots of
>> levelplot.  Levelplot function works quite ok but when I call this plot
>> (p) and plot with layer(sp.polygons(afr)), I get this error:
>>
>> Error in get(x, envir = this, inherits = inh)(this, ...) :
>>     Need at least one of stat and geom
>>
> [...]
>> sessionInfo()
>> R version 2.14.1 (2011-12-22)
>> Platform: i386-pc-mingw32/i386 (32-bit)
> [...]
>> other attached packages:
>>    [1] maps_2.2-5          fts_0.7.7           ggplot2_0.8.9
>> proto_0.3-9.2       reshape_0.8.4
>>    [6] plyr_1.7.1          ncdf_1.6.6          rasterVis_0.10-9
>> hexbin_1.26.0       latticeExtra_0.6-19
>> [11] RColorBrewer_1.0-5  raster_1.9-67       maptools_0.8-14
>> lattice_0.20-3      sp_0.9-95
>> [16] foreign_0.8-49
>>
>> loaded via a namespace (and not attached):
>> [1] zoo_1.7-7
> Hello,
>
> Both ggplot2 and latticeExtra define a "layer" function. You have to
> call library(latticeExtra) *after* library(ggplot2) to use the
> latticeExtra::layer mechanism instead of ggplot2::layer.
>
> Best.
>
> Oscar
>