[postgis-users] segmenting a linestring geometry

[Simon Greener]

You could do the ST_Segmentize and then use my GetVector function to explode the line at those points.

http://www.spatialdbadvisor.com/postgis_tips_tricks/128/exploding-a-linestring-or-polygon-into-individual-vectors-in-postgis

The only thing is that ST_Segmentize may introduce shorter vectors around the existing vertices as in the following example:

select ST_Distance(ST_MakePoint((vect.*).startcoord.x,(vect.*).startcoord.y),
                    ST_MakePoint((vect.*).endcoord.x,(vect.*).endcoord.y))
   from ST_GetVector(ST_Segmentize('LINESTRING(0 0, 1 1, 2 2, 3 3)'::geometry,0.25)) as vect;

st_distance
double precision
----------------
0.25
0.25
0.25
0.25
0.25
0.164213562373095
0.25
0.25
0.25
0.25
0.25
0.164213562373094
0.25
0.25
0.25
0.25
0.25
0.164213562373094

HTH

regards
Simon

On Tue, 03 Apr 2012 03:38:02 +1000, Ed Linde <edolinde at gmail.com> wrote:

> Hi All,
> I see that ST_Segmentize allows me to introduce points to a line string "x" meters apart. I was wondering ifthere was a way to break the line string so that I can get lines "x" meters in length returned as separate rows..
> all belonging to the one segment ID?
>
> Cheers,
> Ed
>



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