Export akima grid with gdal

On Wed, 24 Oct 2007, Michael Sumner wrote:

Hi, not sure if sp already has something like this, but it's fairly
simple anyway. I have this function in the package "trip". "x" is a
standard R XYZ list object, as expected by image():


image2Grid <-
function (x, p4 = NA)
{
   if (!all(names(x) %in% c("x", "y", "z")))
       stop("image must have components x, y, and z")
   cells.dim <- dim(x$z)
   xx <- x$x
   yy <- x$y
   lx <- length(xx)
   ly <- length(yy)
   if (all(c(lx, ly) == (cells.dim + 1))) {
       print("corners")
       xx <- xx[-1] - diff(xx[1:2])/2
       yy <- yy[-1] - diff(yy[1:2])/2
   }
   SpatialGridDataFrame(GridTopology(c(xx[1], yy[1]), c(diff(xx[1:2]),
       diff(yy[1:2])), cells.dim), data.frame(z = as.vector(x$z[,
       ncol(x$z):1])), proj4string = CRS(p4))
}

There is a method to coerce from a matrix to a SpatialGridDataFrame, 
but not for the (x, y, z) list case - if it would be sensible, and if 
you agree, we could easily add it.

Roger

==============Original message text===============
On Wed, 24 Oct 2007 12:34:17 +1100 paallen at attglobal.net wrote:

Hi all,

I have gridded some data using akima's
interp.new() function.  I now want to export to
something that ArcGIS can read directly.  I was
thinking about something like a geotiff, or a
simple bil.

How do I export this akima list object using gdal?
In know that I have to convert the list to a
spatialgrid but I just cannot manage it.

thanks,

Phillip J. Allen
Geochemist.