From: Regina Obe <lr@pcorp.us>
Date: Fri, 1 Sep 2017 13:58:46 +0000 (+0000)
Subject: Note that ST_Intersection drops M
X-Git-Tag: 2.4.0beta1~2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4917be69de8c5cfc7774f89133f99f5fd8e8c1c5;p=postgis

Note that ST_Intersection drops M
References #3826 for PostGIS 2.4.0

git-svn-id: http://svn.osgeo.org/postgis/trunk@15611 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/doc/reference_processing.xml b/doc/reference_processing.xml
index bea92fc59..dcd0384ee 100644
--- a/doc/reference_processing.xml
+++ b/doc/reference_processing.xml
@@ -1810,6 +1810,8 @@ Returns a geometry that represents the shared portion of geomA and geomB.
 			<para>Do not call with a <varname>GEOMETRYCOLLECTION</varname> as an argument</para>
 		  </important>
 
+	  	<warning><para>This function will drop the M coorindate values if present.</para></warning>
+
 		  <warning><para>If working with 3D geometries, you may want to use SFGCAL based <xref linkend="ST_3DIntersection" /> which does a proper 3D intersection for 3D geometries.  Although this function works with Z-coordinate, it does an averaging of Z-Coordinate values when <code>postgis.backend=geos</code>. <code>postgis.backend=sfcgal</code>, it will return a 2D geometry regardless ignoring the Z-Coordinate. Refer to <xref linkend="postgis_backend" /> for details.</para></warning>
 
 		  <para>Performed by the GEOS module</para>