assertion failure on call to r.cost & v.what.rast
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"
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