[postgis-users] function from multilinestring to linestring

[Markus Schaber]

Hi, toni,

toni hernnadez wrote:

> Up to now I've using the 1.1.1 version of postgis.

>From the documentation:
> LineMerge(geometry)
> 
> Returns a (set of) LineString(s) formed by sewing togheter costituent linework of input. 
> 
> Availability: 1.1.0 - requires GEOS >= 2.1.0

So your PostGIS version should have linemerge, but maybe your geos is
too old. But updating to 1.1.2 would be a good idea nevertheless, as it
contains bugfixes.

navteq=# select asText(linemerge('MULTILINESTRING((498376.89
651569.6,498372.28 651571.89),(498372.28 651571.89,498371.77
651576.05))'));
astext
------------------------------------------------------------------------
 LINESTRING(498376.89 651569.6,498372.28 651571.89,498371.77 651576.05)


> select astext(geomunion(geomfromtext('MULTILINESTRING((498376.89
> 651569.6,498372.28 651571.89),(498372.28 651571.89,498371.77
> 651576.05))',23031)))

Okay, you're right. I can reproduce this here.

It seems I misunderstood geomunion.


HTH,
Markus
-- 
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

Fight against software patents in EU! www.ffii.org www.nosoftwarepatents.org