Обсуждение: How to create Geo Types from numeric?

Hi!

I'm trying to fill a table which has a polygon-type column from another
table with discrete numeric data. It contains circle descriptions by x,y,r
components in seperate columns.

There is a nice polygon() functions which can estimate circles by
polygons. Another one converts a point and radius to a circle
(circle(point, r)). But with which function may i generate a point from
two discrete coordinates? I imaginge something like that:

 =polygon( circle( point( oldx, oldy ), radius )

But where is the desired point() function?

Thank you very much!
Klaus

Am Fri, 21 Jan 2005 18:43:01 +0100 schrieb Klaus:

> But where is the desired point() function?

*argh* Maybe i should have simply tried it out :-).
Even althought i could not find it in the docs at first glance....
It works :-)

On Fri, Jan 21, 2005 at 06:43:01PM +0100, Klaus wrote:

> There is a nice polygon() functions which can estimate circles by
> polygons. Another one converts a point and radius to a circle
> (circle(point, r)). But with which function may i generate a point from
> two discrete coordinates? I imaginge something like that:
>
>  =polygon( circle( point( oldx, oldy ), radius )
>
> But where is the desired point() function?

\df point
                             List of functions
 Result data type |   Schema   | Name  |        Argument data types
------------------+------------+-------+------------------------------------
...
 point            | pg_catalog | point | double precision, double precision
...

SELECT point(10, 20);
  point
---------
 (10,20)
(1 row)

How are you trying to use point(), what are you expecting to happen,
and what actually does happen?

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

"Klaus W." <DELTHISvortex25@gmx.de> writes:
> Am Fri, 21 Jan 2005 18:43:01 +0100 schrieb Klaus:
>> But where is the desired point() function?

> *argh* Maybe i should have simply tried it out :-).
> Even althought i could not find it in the docs at first glance....
> It works :-)

Hmm, I don't see it in the docs either --- looks like a documentation
oversight.

            regards, tom lane