[R-sig-Geo] readRAST6: too many open files

[Roger Bivand]

On Tue, 5 May 2009, Roger Bivand wrote:

> On Tue, 5 May 2009, Agustin Lobo wrote:
>
>> Roger,
>> 
>> After upgrading, the test works with plugin=F,
>> while plugin=T produces the same result.
>> 
>
> I find this too on Fedora 10, plugin=TRUE fails after a hundred or so calls, 
> and then crashes R on a further command. With plugin=FALSE, there is no 
> problem at all. The problem then lies in the plugin driver, which isn't 
> anything that spgrass6 can do anything about. It looks as though the plugin 
> is opening file handles to GRASS files but not closing them. I'll try to ask 
> on the GDAL and grass-dev lists. For the time being, it seems best to use 
> plugin=FALSE in readRAST6().

A follow-up. The previous results were using a GDAL 1.5.3 RPM, linking 
against GRASS 6.3 libraries. Having built a fresh GDAL 1.6.0 from source, 
linked against a fresh GRASS 6.4.0 RC4, the plugin now works and does not 
crash R. Browsing the GDAL GRASS raster plugin, there seem to have been 
important commits between GDAL 1.5.3 and 1.6.0 (possibly also 1.5.4, 
untested). GRASS has also changed between 6.3 and 6.4.0 release 
candidates. So a possible solution is to upgrade both GDAL and GRASS, or 
at least GDAL.

Roger

>
>> Also, ignore.stderr=T yields:
>> 
>> ERROR 6: SetColorTable() only supported for Byte or UInt16 bands in TIFF 
>> format.
>
> This is a GRASS version issue, more recent GRASS support a flag to avoid 
> r.out.gdal trying to write non-existent colour tables. Could you repeat your 
> GRASS version:
>
> execGRASS("g.version")
>
> should do it.
>
>> WARNING: Input raster map constains cells with NULL-value (no-data). The
>>         value 999 was used to represent no-data values in the input
>>         map.You can specify nodata value by nodata parameter.
>
> Maybe set a NODATA= value in the readRAST6() call to avoid heuristics trying 
> to find a possible value?
>
> Roger
>
>> /media/Transcend/Montseny/GrassData//carlos/A_TOTAL/.tmp/caminoccg/nomdum 
>> has GDAL driver GTiff
>> and has 94 rows and 116 columns
>> 
>> which is not including any more the first lines that we had with the 
>> previous version:
>> 
>> raster map/current region mismatch detected in components:
>>           cols            rows origin.northing  origin.easting
>>           TRUE            TRUE           FALSE            TRUE
>> set plugin=TRUE to override; continuing with plugin=FALSE
>> 
>> Now we have:
>> 
>>> sessionInfo()
>> R version 2.9.0 (2009-04-17)
>> i486-pc-linux-gnu
>> 
>> locale:
>> LC_CTYPE=es_ES.UTF-8;LC_NUMERIC=C;LC_TIME=es_ES.UTF-8;LC_COLLATE=es_ES.UTF-8;LC_MONETARY=C;LC_MESSAGES=es_ES.UTF-8;LC_PAPER=es_ES.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;LC_MEASUREMENT=es_ES.UTF-8;LC_IDENTIFICATION=C
>> 
>> attached base packages:
>> [1] stats     graphics  grDevices utils     datasets  methods   base
>> 
>> other attached packages:
>> [1] spgrass6_0.6-4 XML_1.95-3     rgdal_0.6-7    sp_0.9-36
>> 
>> loaded via a namespace (and not attached):
>> [1] grid_2.9.0      lattice_0.17-22
>>> 
>> 
>> We are trying now with our process, that takes much longer than the test, 
>> we'll let you know.
>> 
>> Thanks!
>> 
>> Agus
>> 
>> 
>> 
>
>

-- 
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.Bivand at nhh.no