[postgis-users] Select junctions in linear dataset

[Kevin Neufeld]

Selecting the start and endpoint in a fully-noded linear dataset has 
always worked for me to get the junctions.  Why does it not give you the 
desired result?  What's happening?

-- Kevin

On 12/16/2010 1:52 AM, Thomas Kouk wrote:
> Hi all,
> I am newbie in postgis. I have a linear dataset (road network) and I 
> want to select the junctions (in order to count them and maybe isolate 
> them in a seperate point table). ST_StartPoint and ST_EndPoint do not 
> give me the desired result, no matter how I combine them. Is there 
> another way or a function that I could use?
> Alternatively I could create a loop in php to examine each feature and 
> to find for each end-point if there is other feature in zero 
> distance... however I think that this would be a really painfull and 
> long lasting procedure, especially in case of dense data. There should 
> be a simpler way...
> Thanks,
> Thomas
>
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