[postgis-tickets] [PostGIS] #2192: Add tolerance parameter to ST_Split for splitting lines by points

[PostGIS]

#2192: Add tolerance parameter to ST_Split for splitting lines by points
---------------------------------+------------------------------------------
 Reporter:  michischolz          |       Owner:  pramsey      
     Type:  enhancement          |      Status:  new          
 Priority:  medium               |   Milestone:  PostGIS 2.0.3
Component:  postgis              |     Version:  2.0.x        
 Keywords:  st_split, tolerance  |  
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 Heho.
 ST_Split does not work well when splitting a line by a point. Consider the
 following example where the line is not split even though the blade is
 supposed to be a point on the line:

 {{{
 SELECT ST_AsText((ST_Dump(ST_Split(lin.geom,
 ST_Line_Interpolate_Point(lin.geom, 0.5)))).geom) AS geom
 FROM (SELECT ST_GeomFromText('LINESTRING(604630.408 5792499.778,604623.849
 5792500.886)') AS geom) AS lin
 }}}

 For the case of a line split by a point some kind of tolerance parameter
 would help. Until now I it is necessary first to ST_Snap your line to that
 interpolated point before splitting it by the point, which is not
 straightforward (thanks to strk for this hint). At least you could mention
 this hint in the documentation.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/2192>
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