Re: query question really cant give a summary here so read the body ; -)

Yes, PostGIS LINESTRINGS, no not ST_AsEWKT(). By similar configuration I
mean shape. So I can identify two lines if they have a similar shape. No not
ST_Distance()....and don't call me Shirley.

I also neglected to include the query in my previous post.

SELECT a.id,b.id FROM subsumed_secondary a
INNER JOIN subsumed_secondary b ON a.geom && b.geom AND a.id <> b.id
WHERE dev.line_descriptor_2(simplify(a.geom,1.5)) =
dev.line_descriptor_2(simplify(b.geom,1.5))

On Fri, Apr 25, 2008 at 12:07 PM, Colin Wetherbee <cww(at)denterprises(dot)org>
wrote:

> Rhys Stewart wrote:
>
>> The example I provided earlier was a very simplified model of the table
>> I'm working with after a self join. The table in question contains
>> geographic data (linestrings)
>>
>
> PostGIS LINESTRINGs?
>

>
> > and I have written a function to return a
>
>> textual representation
>>
>
> Like ST_AsEWKT()?
>
> > so that I can easily identify lines with similar
>
>> configuration. I want to now select lines that are in close proximity to
>> each other and have the same configuration. So this requires a self join
>> (afaik). So, short of a function like the one that was posited earlier, is
>> there a method using just plain old sql to get the results I desire?
>>
>
> Surely, you don't mean ST_Distance()?
>
> What do you mean by "similar configuration"?
>
> Colin
>