Re: how to identify outliers

Rhys A.D. Stewart wrote:
> Hey all,
> I have the following table:  data(pnum text, distance float8, route text).
> I would like to remove the outliers in distance, i.e. lets say i get
> the avg dist of pnum for each route and the std deviation of the
> distance what is the best way to identify the outliers?
>

i dunno.  brute force, two passes, one to identify the MIN and MAX of
the values, then another SELECT avg(value) ....   WHERE (....) AND val
!= minval AND val != maxval.

you could probably do something with a standard deviation that is more
accurate for large sets than just tossing the 2 outliers.