[geos-devel] [GEOS] #1007: GEOSNearestPoints_r for prepared geometries

GEOS geos-trac at osgeo.org
Tue Dec 17 13:34:08 PST 2019

#1007: GEOSNearestPoints_r for prepared geometries
 Reporter:  ndawson      |       Owner:  geos-devel@…
     Type:  enhancement  |      Status:  new
 Priority:  minor        |   Milestone:
Component:  Default      |     Version:
 Severity:  Unassigned   |  Resolution:
 Keywords:               |

Comment (by ndawson):

 > perhaps the "polygon label point" function could be provide entirely by

 Is this the same as the "pole of inaccessibility"? If so, then I'd say
 that would be very welcome in GEOS. However, it couldn't be used in the
 QGIS labeling engine because we need to generate many candidates, not just
 a single one. In fact, a wide geographic spread and coverage of the
 polygon by the candidates is what we most require (As it gives the
 labeling problem solver more options to work with vs a cluster of
 candidates centered around one point).

 The current QGIS algorithm is quite rudimentary, as it just halves the
 grid cell size each iteration until a sufficient number of candidates
 located inside the polygon have been generated. It's on my todo list to
 refine this, likely via a modification of the polylabel algorithm so that
 the grid cells further from the boundary are the most likely to be refined
 when more candidates are required (i.e. complete coverage of the whole
 polygon on the first iteration, then successive iterations give more
 candidates towards the middle of the polygon).

Ticket URL: <https://trac.osgeo.org/geos/ticket/1007#comment:7>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).

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