Opened 19 months ago

Closed 8 months ago

#4939 closed enhancement (duplicate)

Add possibility to merge lines without changing order of points.

Reported by: evgen Owned by: komzpa
Priority: medium Milestone: PostGIS 3.3.0
Component: postgis Version: 2.5.x
Keywords: Cc:

Description

There is a great function ST_LineMerge. But it could reverse lines in multiline to connect them. E.g.

` SELECT ST_AsText(ST_LineMerge( ST_GeomFromText('MULTILINESTRING((-29 -27,1 2),(-29 -27,-45 -33),(-45 -33,-46 -32))')) ); ` returns LINESTRING(1 2,-29 -27,-45 -33,-46 -32) but it could be MULTILINESTRING((-29 -27,1 2),(-29 -27,-45 -33,-46 -32))'.

I process one way roads. When I merge them I'd like to keep point order to know original direction of that segments.

Change History (9)

comment:1 by pramsey, 18 months ago

Milestone: PostGIS 3.1.3PostGIS 3.1.4

comment:2 by pramsey, 18 months ago

Resolution: wontfix
Status: newclosed

This seems unlikely to happen (when directions of merged lines disagree then…?) It's also something that can be reported upstream in the JTS repository. If there's interest there, or it's easy, it will eventually flow downstream to here.

comment:3 by komzpa, 18 months ago

Resolution: wontfix
Status: closedreopened

This is actual and needed in generating maps with one-way roads. If directions disagree don't merge.

comment:4 by komzpa, 18 months ago

Owner: changed from pramsey to komzpa
Status: reopenednew

comment:5 by robe, 17 months ago

Milestone: PostGIS 3.1.4PostGIS 3.2.0

Slating for 3.2.0 as it sounds like a behavior change rather than a bug. Might even need to go to 3.3.0 if we need to introduce a new arg.

comment:6 by mdavis, 17 months ago

Logged as JTS-773.

This is a worthwhile enhancement to JTS and GEOS. It could be exposed in PostGIS as an option to ST_LineMerge.

comment:7 by robe, 15 months ago

Milestone: PostGIS 3.2.0PostGIS 3.3.0

comment:9 by robe, 8 months ago

Resolution: duplicate
Status: newclosed

duplicates #5161

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