[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 Fund Me
 Component:  postgis      |    Version:  2.0.x
Resolution:               |   Keywords:  st_split, tolerance, gsoc
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Comment (by Mike Taves):

 FYI, a simple implementation of this feature is:
 {{{
 CREATE OR REPLACE FUNCTION ST_Split(geom1 geometry, geom2 geometry, double
 precision)
   RETURNS geometry AS 'SELECT ST_Split(ST_Snap($1, $2, $3), $2)'
   LANGUAGE sql IMMUTABLE STRICT COST 10;
 }}}
 However, it's not ideal:
 {{{
 SELECT ST_AsText(ST_Split('LINESTRING(0 0, 2 0)', 'MULTIPOINT(0 0, 1
 0.0001)', 0.001));
 -- Returns: GEOMETRYCOLLECTION(LINESTRING(1 0.0001,2 0),LINESTRING(0 0,1
 0.0001))
 -- Expected: GEOMETRYCOLLECTION(LINESTRING(1 0,2 0),LINESTRING(0 0,1 0))
 }}}

 Ideally the C-level logic would use `lwgeom_snap` and
 `lwline_interpolate_points` to handle a third `tolerance` parameter.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/2192#comment:8>
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