Re: Creating Aggregate functions in PLpgSQL

--- On Tue, 12/11/07, Matthew Dennis <mdennis(at)merfer(dot)net> wrote:

> http://www.postgresql.org/docs/8.3/static/sql-createaggregate.html
> is for
> 8.3 where there were some changes to the number of
> arguments an aggregate
> could take. I believe it's also more descriptive
> documentation.
>
> of course for things like average you wouldn't need a
> custom type...

Thanks for the information it is very useful. The reason that I ask, is that I am trying to develop a way to calculate the average power factor(scalar) of a Motor Control Center (among other things). The Electrical Engineers that are asking for the report introduced me to a rather complicated formula to implement in standard SQL.

The best way that I can describe the problem get the PF is finding the angle between Xcomp/hypotenuse after having used Pythagorean theorem to find the hypotenuse after having summing of multiple 2 coordinate vectors(the EEs use the term phasers) for each MCC cubical.

It seems they have need for quite a few other little aggregate functions that they would like me to make if I can get this one done first.

Anyway thank for the push in the right direction!

Regards,
Richard Broersma Jr.

Anyway