On Monday 19 April 2010, Rich Shepard wrote: > For a scientific database holding observed and measured values there are > two non-numeric (NAN) legitimate entries: <1 and 'below detection limits.' > Is anyone aware of a standard way of expressing these? > > The problem is that the column needs to be of a numeric type because the > numbers will be manipulated mathematically and summarized statistically. So > a NAN such as '<1' or 'BDL' doesn't cut it. > > Any thoughts? >
how about NULL ? Dylan -- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/ University of California at Davis 530.754.7341 _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
