Functions to implement from GEOS

[jorisvandenbossche]

Opening a similar issue here as we had at pygeos/pygeos#126.
GEOS changelog at https://github.com/libgeos/geos/blob/master/NEWS.md

This issue lists GEOS functions that could be exposed in Shapely as new public functions as well.

GEOS <= 3.8:

• GEOSOrientationIndex
• GEOSNode -> ENH: Add node function #1431
• GEOSisValidDetail
• GEOSGeomGetEndPoint
• GEOSGeomGetStartPoint
• GEOSMinimumClearanceLine
• GEOSMinimumWidth
• GEOSRelateBoundaryNodeRule (GEOSRelatePatternMatch)
• GEOSDistanceIndexed
• GEOSSegmentIntersection
• GEOSPolygonize_valid

GEOS 3.9:

• GEOSPreparedDistance
• GEOSMaximumInscribedCircle -> ENH: add maximum_inscribed_circle (polylabel) #1307
• GEOSLargestEmptyCircle -> ENH: add maximum_inscribed_circle (polylabel) #1307

GEOS 3.10:

• GEOSMakeValidWithParams (ENH: expose MakeValid parameters, introduced with GEOS 3.10.0 #1415)
• GEOSWKBWriter_setFlavor -> ENH: expose flavor keyword in to_wkb #1628
• GEOSConstrainedDelaunayTriangulation -> ENH: Add constrained_delaunay_triangles function #1685

GEOS 3.11:

• GEOSGeom_transformXY (Feature: transform XY #1400)
• GEOSHilbertCode (Feature: Hilbert code  #1398)
• GEOSConcaveHull (Feature: concave hulls #1296) -> ENH: Add concave_hull() function #1518
• GEOSConcaveHullOfPolygons
• GEOSPolygonHullSimplify
• GEOSPolygonHullSimplifyMode
• GEOSLineMergeDirected -> ENH: Add directed parameter to line merge #1592
• GEOSWKBReader_setFixStructure
• GEOSWKTReader_setFixStructure (ENH: expose fix_structure keyword in WKT reader (close linestrings automatically) #1342)

GEOS 3.12:

• GEOSPreparedIntersectsXY and GEOSPreparedContainsXY -> ENH: faster contains_xy/intersects_xy predicates special casing for point coordinates #1548
• GEOSLineSubstring
• GEOSDisjointSubsetUnion
• GEOSHasM
• GEOSGeomGetM
• GEOSEqualsIdentical
• GEOSOrientPolygons
• GEOSConcaveHullByLength
• GEOSCoverageIsValid, GEOSCoverageSimplifyVW
  • ENH: add coverage_simplify exposing topological simplification of coverages #1969
• GEOSGeom_releaseCollection

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If other functions with the same signature are already exposed, adding a new GEOS function to Shapely can be quite straightforward, see #1431 as an example

[akadouri]

It looks like GEOSGeomGetEndPoint and GEOSGeomGetStartPoint are wrappers around similar methods in the geos LineString class. Does it make sense to add similar methods to the shapely LineString class as well as add those functions?

[jorisvandenbossche]

That makes me also realize we already expose get_point (the getPointN that is used the code you link to), so you can already get the start and end point of a line similarly with shapely.get_point(line, 0) and shapely.get_point(line, -1).
So that makes it maybe less needed to directly expose GEOSGeomGetEndPoint and GEOSGeomGetStartPoint? (we could still add start_point and end_point attributes to the LineString class if we would want that)

[akadouri]

Oh I didn't know that existed. I have.coords[0] and .coords[-1] littered all over scripts, these new methods would be more explicit and prevent typos (like using [1] instead of [-1]) but don't seem like high priority adds if there are two other ways to do the same thing.

[chourmo]

Cluster functions would be super handy.
https://github.com/libgeos/geos/tree/6ea4e94e9c3a8d14ee9950f7e12eef273c74047c/include/geos/operation/cluster

[jorisvandenbossche]

@chourmo I don't think those have been exposed through their C API, so that would an enhancement that first need to be brought up with GEOS

[mwtoews]

See libgeos/geos#823 to hopefully implement a C API for clustering. This is not trivial, some discussion may be needed to refine the best strategy for the implementation.