[postgis-devel] [PostGIS] #892: Smarter linear location (for ST_Line_Interpolate_Point, ST_Line_Substring, ST_Line_Locate_Point)
PostGIS
trac at osgeo.org
Tue Mar 29 07:26:15 PDT 2011
#892: Smarter linear location (for ST_Line_Interpolate_Point, ST_Line_Substring,
ST_Line_Locate_Point)
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Reporter: strk | Owner: pramsey
Type: enhancement | Status: new
Priority: medium | Milestone: PostGIS 2.0.0
Component: postgis | Version: trunk
Keywords: |
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ST_LocatePoint returns a value which you can't easily convert to a vertex
number. This isn't helpful if what you're looking for is a substring
formed by pre-existing vertices rather than formed by arbitrarily
interpolated points.
In turn, re-using existing vertices is required to avoid introducing
coordinates drifts when willing to analize subportions of lines.
GEOS/JTS, for comparison, uses a pair of (SEG_NUM/SEG_FRACTION)
representing in turn the segment index and the fraction of next segment.
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Ticket URL: <http://trac.osgeo.org/postgis/ticket/892>
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