Solved! (was Re: [GRASS-user] v.dissolve - is this a bug?)
In case anyone's wondering, I found out what happens. The issue is the handling of case by the OSX command line. Most of the time, the OSX command line ignores case. For example: v.clean MyMap output=CleanMap option=break,snap works the same as: v.clean mymap output=cleanmap option=break,snap The only difference is that the output file name is cased - but a case-less input of a cased name works. However, database handling is sometimes case-sensitive. If I create the column using v.db.addcol: v.db.addcol MyMap columns=Dissolve int then these will behave the same: v.db.update MyMap column=dissolve value=1 and v.db.update MyMap column=Dissolve value=1 However, v.dissolve will notice the difference! v.dissolve MyMap output=MyMap_Dissolved column=Dissolve -- works v.dissolve MyMap output=MyMap_Dissolved column=dissolve ERROR: Key column must be of type integer or string I would file this in the tracker, but there's nobody around to reset my password! So: in using v.dissolve, beware of case. Cheers, Richard On 16/08/10 6:08 PM, Markus Neteler wrote: On Sat, Aug 14, 2010 at 10:16 AM, Richard Chirgwin rchirg...@ozemail.com.au wrote: Hi, In running v.dissolve within a script, I am getting an intermittent failure: ERROR: key column must be integer or string Here's the script spot that fails (but only sometimes) v.db.addtable MAP v.db.addcol MAP columns=Dissolve int At this point, please run v.info -c MAP and report here. v.db.update MAP column=Dissolve value=1 v.dissolve MAP output=DISSOLVE column=Dissolve The killer is that it isn't reliable - sometimes it works, sometimes it fails, and I can't tell why! Always on the same machine, the same binary and the same map? Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.dissolve - is this a bug?
On Sat, Aug 14, 2010 at 10:16 AM, Richard Chirgwin rchirg...@ozemail.com.au wrote: Hi, In running v.dissolve within a script, I am getting an intermittent failure: ERROR: key column must be integer or string Here's the script spot that fails (but only sometimes) v.db.addtable MAP v.db.addcol MAP columns=Dissolve int At this point, please run v.info -c MAP and report here. v.db.update MAP column=Dissolve value=1 v.dissolve MAP output=DISSOLVE column=Dissolve The killer is that it isn't reliable - sometimes it works, sometimes it fails, and I can't tell why! Always on the same machine, the same binary and the same map? Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.dissolve - is this a bug?
On Mon, Aug 16, 2010 at 10:14 AM, Nikos Alexandris nikos.alexand...@felis.uni-freiburg.de wrote: Richard Chirgwin: ... The killer is that it isn't reliable - sometimes it works, sometimes it fails, and I can't tell why! Always on the same machine, the same binary and the same map? Markus, Richard, in the past I witnessed some strange randomness myself. Can't find the post anymore (where Markus was referring to Heisenberg or someone's uncertainty theory?). You mean Heisenbug: On Tue, Sep 23, 2008 at 8:55 PM, Glynn Clements gl...@gclements.plus.com wrote: [ .. referring to memory corruption ...] It doesn't help that such bugs often fail to manifest if the program is run under a debugger (colloquially referred to as a Heisenbug, in reference to the quantum mechanics principle that simply observing a system can change its behaviour). So far we are far away from such a bug, also since v.dissolve is simply a script. First we need to obtain answers to above questions. Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] v.dissolve - is this a bug?
Markus Neteler wrote: On Mon, Aug 16, 2010 at 10:14 AM, Nikos Alexandris nikos.alexand...@felis.uni-freiburg.de wrote: Richard Chirgwin: ... The killer is that it isn't reliable - sometimes it works, sometimes it fails, and I can't tell why! Always on the same machine, the same binary and the same map? Markus, Richard, in the past I witnessed some strange randomness myself. Can't find the post anymore (where Markus was referring to Heisenberg or someone's uncertainty theory?). You mean Heisenbug: On Tue, Sep 23, 2008 at 8:55 PM, Glynn Clements gl...@gclements.plus.com wrote: [ .. referring to memory corruption ...] It doesn't help that such bugs often fail to manifest if the program is run under a debugger (colloquially referred to as a Heisenbug, in reference to the quantum mechanics principle that simply observing a system can change its behaviour). So far we are far away from such a bug, also since v.dissolve is simply a script. First we need to obtain answers to above questions. Markus Markus, I will try to get it to reproduce, and post the results here. Cheers, Richard Chirgwin ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
