Opened 10 months ago

Closed 8 months ago

#5373 closed enhancement (fixed)

Expose GEOSLargestEmptyCircle

Reported by: mdavis Owned by: pramsey
Priority: medium Milestone: PostGIS 3.4.0
Component: postgis Version: master
Keywords: Cc:

Description

GEOS has recently enhanced LargestEmptyCircle so that it works correctly with polygonal boundaries. See the JTS PR for more information. It would be nice to expose this in PostGIS.

Currently the LEC functionality is accessed via ST_MaximumInscribedCircle when the input is non-polygonal (lines and/or points). I suggest exposing it directly via a new function ST_LargestEmptyCircle(geom, boundary, tolerance). This has the advantages:

  • it provides an explicit boundary constraint polygon. This will support queries such as "Find the furthest point in a jurisdiction from all roads".
  • it will allow polygonal obstacles (in the future, once the underlying algorithm is enhanced)
  • it allows more focussed documentation and examples

The boundary is optional; if not provided the convex hull of the obstacles is used. Perhaps the function signature should allow the boundary parameter to be optional? Or else it can be allowed to be NULL.

The existing ST_MaximumInscribedCircle behaviour can be left unchanged for backwards compatibility.

Change History (2)

comment:1 by robe, 10 months ago

Milestone: PostGIS 3.3.3PostGIS 3.4.0
Version: 3.3.xmaster

comment:2 by pramsey, 8 months ago

Resolution: fixed
Status: newclosed
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