Something seems to have changed, since 2006 ... The following should work:
library(sp)
d <- list(x =1:10, y = 22:31, z = matrix(1:100, 10, 10))
image(d)
gt <- GridTopology(cellcentre.offset = c(d$x[1], d$y[1]),
cellsize = c(diff(d$x[1:2]), diff(d$y[1:2])), cells.dim = dim(d$z))
grd.atts <- SpatialGridDataFrame(gt, data.frame(depth =
as.vector(d$z[,ncol(d$z):1])))
image(grd.atts, axes=TRUE)
Ian McCallum wrote:
Greetings,
I am trying to export a matrix out to an arcinfo asciigrid.
Write tables might work.
Better is perhaps write.asciigrid or writeGDAL
To do that however, i need to convert my matrix into a Spatial Grid.
I came across a thread (from R. Bivand in 2006) that seems to address
what i need to do.
However if i plug this into R, it fails. I run R 2.10.1 on win XP.
Any ideas on why this is crashing, and how to export a matrix to
arcinfo asciigrid would be great.
Thanks
Ian
> library(sp)
> d <- list(x =1:10, y = 22:31, z = matrix(1:100, 10, 10))
> image(d)
> gt <- GridTopology(cellcentre.offset = c(d$x[1], d$y[1]),
+ cellsize = c(diff(d$x[1:2]), diff(d$y[1:2])), cells.dim = dim(d$z))
> grd.atts <- SpatialGridDataFrame(gt, list(depth =
+ as.vector(d$z[,ncol(d$z):1])))
Error in validObject(.Object) :
invalid class "SpatialGridDataFrame" object: invalid object for
slot "data" in class "SpatialGridDataFrame": got class "list", should
be or extend class "data.frame"
> image(grd.atts, axes=TRUE)
Error in image(grd.atts, axes = TRUE) : object 'grd.atts' not found
___________________________________________
Ian McCallum
Forestry Program
International Institute for Applied Systems Analysis
Schlossplatz 1, A-2361 Laxenburg, Austria
Phone: +43 2236 807-328
Fax: +43 2236 807-599 or 71313
E-mail: mccal...@iiasa.ac.at
Web: http://www.iiasa.ac.at/Research/FOR/
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Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics e.pebe...@wwu.de
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