From: Paul Ramsey Date: Wed, 25 Mar 2015 20:25:23 +0000 (+0000) Subject: Add doc entry for ST_Subdivide X-Git-Tag: 2.2.0rc1~569 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a30078d27d3c7c8606ebf085e276b89ae15e870d;p=postgis Add doc entry for ST_Subdivide git-svn-id: http://svn.osgeo.org/postgis/trunk@13396 b70326c6-7e19-0410-871a-916f4a2858ee --- diff --git a/doc/reference_processing.xml b/doc/reference_processing.xml index 0f53c6732..a4b923965 100644 --- a/doc/reference_processing.xml +++ b/doc/reference_processing.xml @@ -3052,6 +3052,63 @@ MULTILINESTRING((1 3 2.75,1 4 2),(1 1 3,1 2 2.25)) + + + ST_Subdivide + Returns a set of geometry where no geometry in the set has more than the specified number of vertices. + + + + + + setof geometry ST_Subdivide + geometry geom + integer max_vertices=256 + + + + + + Description + + +Turns a single geometry into a set in which each element has fewer than +the maximum allowed number of vertices. Useful for converting excessively +large polygons and other objects into small portions that fit within the +database page size. Uses the same envelope clipping as ST_ClipByBox2D does, +recursively subdividing the input geometry until all portions have less than the +maximum vertex count. + + + Clipping performed by the GEOS module. + Requires GEOS 3.5.0+ + + Availability: 2.2.0. + + + + + Examples + +-- Subdivide a geometry until it all parts have < 50 vertices +SELECT ST_AsText(ST_SubDivide(ST_Segmentize('LINESTRING(0 0, 100 100)'::geometry, 1),50)); + +-- Create a new subdivided table suitable for joining to the original +CREATE TABLE subdivided_geoms AS +SELECT pkey, ST_Subdivide(geom) AS geom +FROM original_geoms; + + + + See Also + +, + + + + + + ST_Union