[postgis-users] Build direction in a network, only from a starting point

[Nicolas Ribot]

Hi,

A recursive CTE query will allow you to walk the network, checking if
startPoint/endPoint of lines are connected as you want.
st_reverse could then be used to correct these lines.
(http://blog.cleverelephant.ca/2010/07/network-walking-in-postgis.html)

Nicolas

On 9 May 2018 at 08:23, aborruso <aborruso at gmail.com> wrote:

> Hi,
> I have a simple network like the one on the left side of the image below.
> The line directions of the left side are the ones I used to draw the lines.
>
> Is there in postgis a function (or an extension) that starting from a
> network, and choosing a starting point (in the image the red one), is able
> to assign/calculate the "right" direction of the network (the one I have on
> the right)?
> I want to "correct" the directions highlighted in green on the right.
>
> Thank you
>
> <http://postgis.17.x6.nabble.com/file/t378582/7xhDhLj.png>
>
>
>
> --
> Sent from: http://postgis.17.x6.nabble.com/PostGIS-User-f3516033.html
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