[postgis-users] break road linestrings intelligently

[Sandro Santilli]

On Tue, Sep 25, 2012 at 07:43:10PM -0600, Richard Greenwood wrote:

> I break the original linestring into 3 new linestrings, but
> how do I populate the "from" and "to" values? If I know the order of
> the 3 new linestrings it would be very easy to calculate the new
> values based on the length of each new linestring, eg. line #1
> 100-240, line#2 241-385, line #3 386-500 or some such thing.

What I've been doing in topology for determining the order has been
comparing the location of a point of each substring against the parent
string. 

--strk; 

 http://www.cartodb.com - Map, analyze and build applications with your data

                                       ~~ http://strk.keybit.net