[postgis-devel] contrib new postgis function

[Emilson Ribeiro Neto]

Dears,
After a specific demand in my work I needed to develop a function to create a single space line from two untouched geometries.
Following is code below if it is interesting to put as new functionality in postgis.

Emilson Ribeiro Neto
best regards

CREATE OR REPLACE FUNCTION public.st_mergecloselines(
geometry, geometry)
    RETURNS geometry
    LANGUAGE 'sql'
-- This function merge two lines that don't within (dont touching) returing a single multiline. By Emilson Ribeiro Neto
AS $BODY$

select ST_LineMerge(st_union(st_union($1,
(case
  WHEN (st_distanceSphere(ST_StartPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_StartPoint($1),ST_EndPoint($2))
                and (st_distanceSphere(ST_StartPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_EndPoint($1),ST_StartPoint($2)))
                and (st_distanceSphere(ST_StartPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_EndPoint($1),ST_EndPoint($2)))
              ) THEN st_makeLine(ST_StartPoint($1),ST_StartPoint($2))

  WHEN   (st_distanceSphere(ST_EndPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_StartPoint($1),ST_EndPoint($2))
                and (st_distanceSphere(ST_EndPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_StartPoint($1),ST_StartPoint($2)))
                and (st_distanceSphere(ST_EndPoint($1),ST_StartPoint($2)) < st_distanceSphere(ST_EndPoint($1),ST_EndPoint($2)))
              ) THEN st_makeLine(ST_EndPoint($1),ST_StartPoint($2))

  WHEN   (st_distanceSphere(ST_StartPoint($1),ST_EndPoint($2)) < st_distanceSphere(ST_StartPoint($1),ST_StartPoint($2))
                and (st_distanceSphere(ST_StartPoint($1),ST_EndPoint($2)) < st_distanceSphere(ST_EndPoint($1),ST_StartPoint($2)))
                and (st_distanceSphere(ST_StartPoint($1),ST_EndPoint($2)) < st_distanceSphere(ST_EndPoint($1),ST_EndPoint($2)))
              ) THEN st_makeLine(ST_StartPoint($1),ST_EndPoint($2))
            else  st_makeLine(ST_EndPoint($1),ST_EndPoint($2))
            end)),$2))

$BODY$
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-devel/attachments/20190822/89c475df/attachment.html>