[R-sig-Geo] Get map of non-NA cells of a stack

[Rafael Wüest]

Hi Johannes,

I don't know of any special function, but you can easily obtain this by combining sum() and is.na() . See the example below:

r <- raster(ncols=36, nrows=18)
r[] <- 1:ncell(r)
r1<-r;r1[sample(1:ncell(r1),20)]<-NA
r2<-r;r2[sample(1:ncell(r2),20)]<-NA
r3<-r;r3[sample(1:ncell(r3),20)]<-NA
s<-stack(r1,r2,r3)

s<-addLayer(s,!is.na(sum(s)))

plot(s)

This may not be the most efficient way to come up with what you want, as summing a big stack may take quite some time, but for small rasters, stacks it certainly works...

HTH, Rafi


On 25.06.2012, at 10:30, Johannes Radinger wrote:

> Hi,
> 
> I have several stacks with different numbers of raster maps. All the stacked rasters have some NA-cells but sometimes in different locations. I'd like to create a raster map of a single stack which indicates cells that are populated in all rasters of that stack (all non-NA cells).
> 
> Is there a special function within the raster package?
> 
> Best regards
> Johannes
> -- 
> 
> Jetzt informieren: http://mobile.1und1.de/?ac=OM.PW.PW003K20328T7073a
> 
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Rafael Wüest
Swiss Federal Research Institute WSL
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