[postgis-users] RE : 3D polyline simplify

[Francois Hugues]

I don't understand what is a 3D polyline.

Your 3D points have x, y coordinates and a z value. If you make your polyline from a selection of points in a raster DEM, you will just have a polyline representing something from the 3D. With st_simplifiy, you will symplify this representation.

Instead your polyline is a multiline, I think you can use st_simplify instead of st_simplifypreservetopology.

Hugues.


-------- Message d'origine--------
De: postgis-users-bounces at postgis.refractions.net de la part de Ed Linde
Date: dim. 17/06/2012 11:30
À: PostGIS Users Discussion
Objet : [postgis-users] 3D polyline simplify
 
Does *ST_SimplifyPreserveTopology : *work with a 3D polyline as well? So if
I had a linestring which I composed from several
3D points using ST_MakeLine, would the DP algorithm still work?

Cheers,
Ed*
*

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