[postgis-users] Extend

[schild]

Hi Shane,

Just an idea - maybe it helps:
- select first and last segment of the line
- calculate distance beetween endpoint of segments and polygon boundary according to the bearing of the linesegments
- extrapolate the linesegments

Have a look at 
https://gis.stackexchange.com/questions/104439/how-to-extend-a-straight-line-in-postgis
and
https://gis.stackexchange.com/questions/33055/postgis-extrapolate-a-line
and last but not least at
http://postgis.net/documentation/


________________________________________

Message: 1
Date: Tue, 16 Oct 2018 21:16:39 +0100
From: Shane Carey <careyshan at gmail.com>
To: postgis-users at lists.osgeo.org
Subject: [postgis-users] Extend line on both sides until it hits
        polygon bondary
Message-ID:
        <CA+jRDxD-q9HrqW1V71-M45zi9mUhM+CS4br-gtEk05eOQZ6S6A at mail.gmail.com>
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Hi,

Is it possible to extend a line on both sides until it hits a polygon
boundary?
Thanks in advance.
Le gach dea ghui,
*Shane Carey*
*GIS and Data Solutions Consultant*