[R-sig-Geo] assertion failure on call to r.cost & v.what.rast

[Colin Bleay]

Roger,

thanks for the response. i will repost on grass-stats.

but to awnser you questions.

There is no security issue, and i have tried pausing with Sys.sleep() 
and using withRestarts () (although i confess I am not confident that i 
have coded this appropriatly).

colin

On 15/12/2010 17:42, Roger Bivand wrote:
> On Wed, 15 Dec 2010, Colin Bleay wrote:
>
>> I am running a script in R that calls functions in grass from a 
>> iterative loop.
>>
>> This works fine but every so often I get an assertion failure.
>>
>> This does not appear to be a function of the data I am sending to the 
>> grass executable.
>
> Colin,
>
> Please repost this on grass-stats:
>
> http://grass.osgeo.org/statsgrass/index.php
>
> as it is only marginally an R question. You may be able to put your 
> execGRASS() calls in a try(), but I suspect that because it is running 
> through system(), the answer is perhaps on the GRASS side, and may not 
> be practical or easy. It may well be that the GRASS program is trying 
> to use resources on your computer that Kerberos has locked - the 
> g_mechListLock variable does not seem to be used in GRASS, and the 
> g_initialize.c file seems to be part of Kerberos, not GRASS. How this 
> works on Windows is not for regular humans to know about, I'm afraid.
>
> Is your machine running under a tight security regime, perhaps? Can 
> you try out your script on a different computer not using networked 
> disk drives? It could also be a function of the environment in which 
> the GRASS Windows binaries were built. Can you try having the repeated 
> calls to execGRASS() separated by pauses, or have it do something else 
> to let Kerberos recover its posture?
>
> Roger
>
>>
>> The assertion failure throws up a window allowing me to 'abort', 
>> 'retry' or 'ignore'.
>>
>> If i 'retry' it then asks me to close the program (the grass 
>> executable) and then the R script carries on as usual. i.e. the retry 
>> works and I will end up with all my data.
>>
>> The problem i have is that I wish to let this r script run over night 
>> but i cannot as I have to be there to supervise it, to 'retry' the 
>> commands.
>>
>> so my questions are:
>>
>> 1. Does any body have any idea why these assertion failures are 
>> occuring?
>> 2. Does anybody have any idea how I might be able to catch these 
>> failures so that I can get R to retry the grass executable rather 
>> than myself.
>>
>> the error the grass executable throws is:
>>
>> "Assertion failed!
>> Program: C\GRASS_64\bin\RCOST~1.EXE
>> File:r:\pismere\athena\auth\krb5\scr\li..\g_initialize.c
>> Line:76
>>
>> Expression: (&(&g_mechListLock)->os)->is_locked==1"
>>
>>
>>
>>
>>
>

-- 
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Dr Colin Bleay
Station d'Ecologie Experimentale du CNRS,
09200 Moulis,
France.

Tel: +33 5 61 04 03 61
Fax: +33 5 61 96 08 51
email: Colin.Bleay at EcoEx-Moulis.cnrs.fr
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