I want to thank you both for your help on this. I
read the C source and the plpgsql below. I think I'm
understanding what I'm seeing.
I will be out of town for several days; but will try
out the plpsql solution next week. (If my luck in
airports holds true, I'll have plenty of time to read
the documentation.)
Thanks again,
Andrew
--- Jeff Davis <list-pgsql-general@empires.org> wrote:
> Yup, I tried the same exact thing :) I wouldn't mind
> seeing some better
> support in plpgsql either. However, anyone can
> create their own type so I
> guess it isn't much of a problem.
>
> I updated my code to use points instead, and more
> meaningful identifiers.
>
>
-----------------------------------------------------------
> create function float_gmean(point) returns float as
> '
> BEGIN
> return ($1[0]^(1/($1[1])));
> END;
> ' language 'plpgsql';
>
> create function float_gmean_accum(point,float)
> returns point as '
> BEGIN
> RETURN point(($1[0]*$2),($1[1]+1));
> END;
> ' language 'plpgsql';
>
> create aggregate gmean
>
(basetype=float,sfunc=float_gmean_accum,stype=point,finalfunc=float_gmean,initcond='(1.0,0.0)');
>
-----------------------------------------------------------
>
>
> > I tried to do this:
> >
> > create function a1(float[2],float) returns
> float[2] as '
> > declare
> > ret float[2];
> > begin
> > ret := $1;
> > ret[1] := ret[1] * $2;
> > ret[2] := ret[2] + 1;
> > return ret;
> > end' language plpgsql;
> >
> > but it failed with syntax errors --- plpgsql
> doesn't understand the
> > notation "var[subscript] := something". Someone
> oughta dig into it
> > and fix that.
> >
> > In the meantime I think the most practical way to
> do this task in
> > plpgsql is to abuse the built-in "point" type,
> which can be treated
> > as an array of 2 floats:
> >
> > regression=# create function a1(point,float)
> returns point as '
> > regression'# begin
> > regression'# return point($1[0] * $2, $1[1] + 1);
> > regression'# end' language plpgsql;
> > CREATE
> > regression=# select a1('(2,3)'::point, 44);
> > a1
> > --------
> > (88,4)
> > (1 row)
> >
> > Note that the subscripts are [0],[1] not [1],[2]
> ... a bit of legacy
> > incompatibility ...
> >
> > regards, tom lane
> >
> > ---------------------------(end of
> broadcast)---------------------------
> > TIP 4: Don't 'kill -9' the postmaster
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