On Fri, Feb 21, 2014 at 3:06 PM, Michel Wortmann <[email protected]> wrote: > Hi list, > I have some (basic) vector related questions: > > After cleaning a vector map, it doesnt have continuous (i.e. no gaps in > numbering) categories, how do I efficiently reset these to so that they have > regular increments (i.e. 1) again? r.clump does something very similar with > vectors. I have tried dropping and adding a new table, deleting and adding > categories with v.category. I thought v.reclass may do the trick but I'd > first need a column with continuous numbers for that.
Hi Michel, perhaps using v.category on layer=2 would to the trick to add new categories? > Somewhat related to this, what is the best/most efficient way of updating an > entire column of a vector table from a numpy array. v.update does do it for > one entry only, i.e. looping would be possible, but that takes ages. Would I > have to go back to using basic sqlite3 packages for that? If you only want to work on a table, then db.execute: http://grass.osgeo.org/grass70/manuals/db.execute.html might be the best. To speed up, put the statements into an SQL transaction. best, Markus -- http://courses.neteler.org/ http://gis.cri.fmach.it/neteler/ _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
