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

[Rich Shepard]

   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?

Rich