On Mon, 1 Mar 2010, Jonathan Greenberg wrote:
As far as sample code goes, simply getting
grass_to_raster=raster("somegrassfile") is my goal -- my understanding
is anything rgdal can read, raster can read. Running your command I
do get:
GRASS (ro): GRASS Database Rasters (5.7+)
But with rgdal:
require(rgdal)
gdaldrivers=getGDALDriverNames()
gdaldrivers$create[gdaldrivers$name=="GRASS"]
[1] FALSE
gdaldrivers$copy[gdaldrivers$name=="GRASS"]
[1] FALSE
gdaldrivers$create[gdaldrivers$name=="GTiff"]
[1] TRUE
gdaldrivers$copy[gdaldrivers$name=="GTiff"]
[1] TRUE
Am I perhaps missing an rgdal installation flag that is required to
enable GRASS rasters?
Unless rgdal was built against and is seeing a different GDAL, there is no
good reason. gdalDrivers() will list all the drivers that the GDAL rgdal
is using sees. However, beware of the plugin, which is notorious for
refering to stale GRASS binaries, and for its choice of exporting the
whole raster with its original resolution, which most often is not the
same as the output of g.region.
To mimic raster, you would use g.region to set the tile size and shape
before using readRAST6() with a temporary file. This could be automated
too, I think.
Hope this helps,
Roger
--j
On Mon, Mar 1, 2010 at 6:04 PM, Dylan Beaudette
<dylan.beaude...@gmail.com> wrote:
Roger can likely point out the problem after some example code is
posted. In the mean time I would suggest checking to make sure your
GDAL is compiled _without_ GRASS support, and that the GDAL GRASS
plugin is correctly installed.
This is how I check on my machine:
gdal_translate --formats | grep -i grass
GRASS (ro): GRASS Database Rasters (5.7+)
Cheers,
Dylan
On Mon, Mar 1, 2010 at 5:44 PM, Alex Mandel <tech_...@wildintellect.com> wrote:
spgrass6 is a an R package and has read/write access to GRASS datasets.
It's usage would be instead of rgdal(well sorta, rgdal is required by
spgrass6). Both write objects to sp types.
You can use it from within R to start a GRASS session or within GRASS to
start a linked R session.
http://cran.r-project.org/web/packages/spgrass6/index.html
I got GDALinfo to work on my machine, I wonder if your just missing the
gdal-grass library, or libgrass.
On ubuntu it's something like libgdal1-1.6.0-grass
I know qgis needs this to work with GRASS not sure about gdal itself but
based on http://gdal.org/frmt_grass.html probably. Also note that page
talks about the path to a dataset that should be used.
Thanks,
Alex
Hmm, I'm trying to use the raster package via rgdal to access these
files -- I'm trying to avoid having to export then to another format
(I'm dealing with gigabytes of rasters), although I suppose I could do
this. Does spgrass6 "enable" rgdal to access GRASS rasters, or is it
its own standalone program? How does the base gdal package work with
grass rasters?
--j
On Mon, Mar 1, 2010 at 2:35 PM, Sarah Goslee <sarah.gos...@gmail.com> wrote:
I think you need to export it from grass first, with r.out.gdal
Or you can use spgrass6 to work with R and GRASS directly.
Sarah
On Mon, Mar 1, 2010 at 5:17 PM, Jonathan Greenberg
<greenb...@ucdavis.edu> wrote:
Folks: when trying to import or GDALinfo a grass raster, where,
exactly, should I be pointing to in the grass directory? I tried
pointing to the file with the same name as the raster I want to work
with in the fcell, cellhd, and cell directories
(grass/location/mapset), but none of these are working... thanks!
--
Sarah Goslee
http://www.functionaldiversity.org
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--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: roger.biv...@nhh.no
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