[GRASS-user] Entering '<1' and 'BDL' in Database

[Dylan Beaudette]

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