Carsten,
Thanks for reporting this. I fixed the NA handling in plotRGB in
raster 1.3-1, which should be available from R-Forge later today, and
from CRAN later this week.
In stead of first reading the data with rgdal, a more direct way to
get at what you want with 'raster' is:
d1 <- stack('Hasenheide')
# or d1 <- brick('Hasenheide')
plotRGB(d1, r=14, g=7, b=1, scale=1)
With the current version, you could perhaps use a work-around like:
d1<-readGDAL('Hasenheide')
d...@data[is.na(d...@data)] <- 0
fn<-stack(raster(d1,14),raster(d1,7),raster(d1,1))
plotRGB(fn,1,2,3, scale=1)
Robert
On Tue, Jul 20, 2010 at 6:27 AM, <carste...@aol.com> wrote:
> Dear list members,
>
> I'm having trouble creating a rgb color composite based one a multiple grid
> object. Both the SGDF2PCT function from rgdal package and the plotRGB
> function from raster package can not handle NA's. For my work it is
> necessary to include No Data values for masking the study area.
>
>
> Is there any way to combine rgdal or raster objects in a rgb color mixture
> with No Data values??? My two approaches are given below.
>
> Very Great Thanks for any help!!!
>
> Carsten
>
> 1. Approach
>
> library(rgdal)
>
> vismaps = readGDAL("Hasenheide")
> vismaps$red = vismaps$band14
> vismaps$green = vismaps$band7
> vismaps$blue = vismaps$band1
>
> ###Display as a RGB image###
> RGBimg = SGDF2PCT(vismaps[c("red", "green", "blue")], ncolors=256,
> adjust.bands=TRUE)
>
> ##########Error in if (bmax == bmin) bmax <- bmin + ncolors :
> missing value where TRUE/FALSE needed################
>
> col<-rgb(d...@data[[4]],d...@data[[7]],d...@data[[1]])
>
> vismaps$idx <- RGBimg$idx
> image(vismaps, "idx", col=RGBimg$ct)
>
>
>
>
> 2. Approach
>
> library(raster)
>
> d1<-readGDAL('Hasenheide')
> fn<-stack(raster(d1,14),raster(d1,7),raster(d1,1))
>
> ###Display as a RGB image###
> plotRGB(fn,scale=1,1,2,3)
>
> ################Error in rgb(getValues(r), getValues(g), getValues(b), max =
> scale) :
> color intensity nan, not in
> [0,1]#############################################
>
>
>
>
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>
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