On Sat, 12 Jun 2010, Markus Neteler wrote:

Dear Roger,

hope all is well.

I came across an issue with readRAST6():

library(spgrass6)
Loading required package: sp
Loading required package: rgdal
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded GDAL runtime: GDAL 1.5.2, released 2008/05/29
Path to GDAL shared files: /home/neteler/binaries/share/gdal
Loaded PROJ.4 runtime: Rel. 4.6.1, 21 August 2008
Path to PROJ.4 shared files: (autodetected)
Loading required package: XML
GRASS GIS interface loaded with GRASS version: 6.4.0svn
and location: patUTM32
mydata_raw <-readRAST6(c("thresh_annual_over_11_celsius_2001_2008_avg", 
"italy_dem20_PHD_zone"), cat=c(FALSE, FALSE))
/home/neteler/grassdata/patUTM32/zanzara_satellite/.tmp/fep/thresh_annual_over_11_celsius_2001_2008_avg
has GDAL driver GTiff
and has 601 rows and 1011 columns
WARNING: The given nodata value is present in rasterband
        <italy_dem20_PHD_zone> and would lead to data loss. Please specify
        a different nodata value with the nodata parameter.
ERROR: Raster export aborted.

Debugging r.out.gdal, I found that the value 10 was used.


GRASS 6.4.0svn (patUTM32): > r.info -r italy_dem20_PHD_zone
min=0
max=3890
GRASS 6.4.0svn (patUTM32): > r.info -t italy_dem20_PHD_zone
datatype=CELL

I hacked in -99999 as NODATA value in the r.out.gdal calls
(spgrass6/R/bin_link.R).

I have no idea why 10 was used but from GRASS 6.4 onwards the r.out.gdal
module has an intelligent NODATA selection thanks to Markus Metz. I can
imagine what you don't want to clutter the code with conditions, but here it
would be great to let the NODATA selection job to r.out.gdal rather than
using the current r.info tricks.

Dear Markus,

The tricks were there for the time when r.out.gdal didn't find its own value, and for the null parameter for r.out.bin. I've moved them down to the r.out.bin branch only, and modified the execGRASS() call to r.out.gdal to omit the nodata= argument by default when NODATA=NULL.

Committed to sourceforge CVS, project r-spatial, module spgrass6. Could you check this and let me know if the problem is resolved?

Best wishes,

Roger


What do you think?

Best,
Markus

PS: off for 2 weeks now
_______________________________________________
grass-stats mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-stats


--
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: [email protected]

_______________________________________________
grass-stats mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-stats

Reply via email to