[GRASS-stats] Error using GRASS from R

[Roger Bivand]

On Wed, 20 Jul 2011, Tim Besser wrote:

> Dear GRASS-community,
>
> I have a very strange problem. I wrote a script in R (2.10.1) for the 
> preparation of my datasets which works fine on my laptop (winxp). I do not 
> start my R session from GRASS but use GRASS through the initGRASS and 
> execGRASS commands. I use the "spgrass6" package and GRASS 6.4.1. As the 
> script would run for days on my old laptop I now got a remote desktop 
> connection to a much faster computer at the university (win7). However, while 
> cmds like r.reclass or r.in.gdal (execGRASS) work on that computer the 
> r.patch (execGRASS) cmd produces following error:

Do not start R in GRASS using initGRASS when you are using an exiting 
location - I will most likely remove this possibility at the next release 
as it confuses users. Start in the usual way by starting GRASS in a 
terminal - text interface - and then start R from the GRASS prompt, or 
use the MSYS console within GRASS (the second of the two GRASS icons).

In your case, I cannot even see why you need R - why not just write a 
shell script, or in GRASS 7 a Python script?

Can you run parseGRASS("r.patch")? What does parseGRASS("r.reclass") 
return? For some reason, your remote Windows GRASS installation appears to 
be treating programs differently. Make sure that you expose the extensions 
when you observe the names of files under Windows - by default it displays 
names without extensions, and a missing extension may be the problem. 
There may also be an issue in the way that Win7 handles DOS-style path 
formats - I have no access to such an OS, so have no idea. I cannot see 
any differences with the Windows native GRASS 6.4.1 on XP.

Createprocess is what starts a new process, and may possibly have 
permissions issues. You'd need to run the same thing locally on an 
identical Win7 system with the same permissions to check. Using a shell 
script would avoid this, I believe.

Roger

>
> execGRASS("r.patch", flags=c("z"), 
> parameters=list(input="mangroves_1989_138_044_LR_recl,mangroves_1989_138_045_UL_recl,mangroves_1989_138_045_UR_recl", 
> output="testomat"), intern=T)
>
> Error in system(cmd0, intern = TRUE) :
>  Createprocess konnte 'C:\GRASS6~1.1\bin\RPATCH~1.EXE 
> --interface-description' nicht ausführen
> Fehler in parseGRASS(cmd) : r.patch not found
>
> I checked the GRASS directory and it is set right in the initGRASS command.
>
> I hope you can help me with one. I have no clue what to do!
>
> Thanks in advance,
>
> Tim
>
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-- 
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
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