[R-sig-Geo] Exporting spatstat 'pixel image' to Arcview 9.x as an e00 or ascii

[Rolf Turner]

This is definitely a case of the blind leading the blind, but I thought 
I'd chip
in anyway.

Let "Im" be your pixel image.  Do:

xy <- as.matrix(as.data.frame(raster.xy(as.owin(Im))))
v <- lookup.im(Im,xy[,1],xy[,2])
A <- SpatialPixelsDataFrame(points=xy,data=data.frame(v))
B <- as(A,"SpatialGridDataFrame")

Then "B" is an object of class "SpatialGridDataFrame" which ***may*** be 
what
you need.  I can't really tell, since I don't understand 
SpatialGridDataFrames.

The foregoing is kludgey, almost surely sub-optimal, and quite possibly 
wrong .....
But there's a chance it will be of some use to you.

     cheers,

         Rolf Turner

On 12/07/11 10:54, Honey-Marie de la Giroday wrote:
> Dear All,
>
> I have a pixel image (im) I received as a .RData file.  I need to
> export this pixel image from R in a file format that can be imported
> into Arcview 9.x (e.g., .e00 or ascii).
>
> Below is some of the code that I have been trying to use.  I have
> reviewed the manuals for rgdal, maptools, sp, and spatstat packages
> but have been unable to find another approach to converting the pixel
> image to an Arcview raster dataset.  Please note that I have also
> searched the R-sig-geo archives and was unable to find this covered
> elsewhere.
>
> "#load spatst package
> library(spatstat)
>
> #load file with model data
> load(file="C:/bestmodel2004.RData")
>
> #Plot best model data for 2004
> plot(bestmodel2004)
>
> #Examine attributes of pixel image
> attributes(bestmodel2004)
> $names
>   [1] "v"      "dim"    "xrange" "yrange" "xstep"  "ystep"  "xcol"   "yrow"
>   [9] "type"   "units"
>
> $class
> [1] "im"
>
> #Load sp package
> library(sp)
>
> #Coerce bestmodel2004 (pixel image) to SpatialGridDataFrame
> #......how do I do this?......
>
> #Output to Acrview = write.asciigrid(x, fname, attr=1, na.value=-9999.....
> #x=SpatialGridDataFrame
> #fname=filename
> write.asciigrid"
>
> Thank you for your time, and please let me know if I need to provide
> further information.
>
> Sincerely,
>
>
>
> H.M.C de la Giroday
>
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