[postgis-users] Computing the lenght of a building's edges looking on a direction

[Paolo Crosato]

Hi,

I have a set of 2d polygons representing buildings. For each one, I have 
to find the lenght of the edges that look towards north.

Here http://imgur.com/HgpO2yH there is a small picture with a test case, 
I have to compute the lenght of the red edges.

Has anybody any suggestion on how to do this in postgis?

Thanks for any input,

Regards

-- 
Paolo Crosato
Software engineer/Custom Solutions
e-mail: paolo.crosato at targaubiest.com