[postgis-users] Selecting pairs of points that have the samedistance between them

[Francois Hugues]

Hello,

 

I may be wrong but I don't see any answer to your question. Below is a request which could do the job you need if I understood it well :

 

Hugues

 

PS : as you can see Nicolas, I learnt from your mail and I'm now able to create a "serial" column into a request ;)

 

create temp sequence myseq increment by 1 Minvalue 1;

 

with mydist as (

 

select nextval('myseq') new_id, a.id id1, b.id id2, st_distance(a.geom, b.geom) dist from my table_of_points a, my table_of_points b

where a.id < b.id

 

)

 

select a.new_id n_id1, b.new_id n_id2, id1, id2  from mydist

where a.new_id < b.new_id

and a.dist = b.dist

 

 

De : postgis-users-bounces at postgis.refractions.net [mailto:postgis-users-bounces at postgis.refractions.net] De la part de Bob Pawley
Envoyé : dimanche 24 juin 2012 20:16
À : postgis-users at postgis.refractions.net
Objet : [postgis-users] Selecting pairs of points that have the samedistance between them

 

Hi

 

I have a geometry of points (more than one pair) that represent the intersections between a line and a column of multistrings. 

 

Can anyone point me to a method of determining which pairs of points are the same distance apart as are other pairs of points.

 

This will isolate the closed object from the open object for me.

 

The srid is all -1.

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