[pgrouting-users] implement directions

[Greg Allensworth]

On 7/30/2012 9:57 AM, Pedro Costa wrote:
> Em 30-07-2012 17:54, Pedro Costa escreveu:
>> Hi guys,
>> Can someone point to me some links or information about implement
>> driving directions in a pgrouting project?
> With driving directions i mean information about the select route like
> "turn right" ...

http://postgis.refractions.net/pipermail/postgis-users/2007-November/017768.html

That's what I was going to use as a start, when I get to that phase of 
our routing system. The "left" or "right" would be the difference 
between the two lines' azimuth: if the difference is positive, and more 
than 0.15 radians then it's a slight right, more than .50 radians it's a 
sharp right, if the difference is negative then it's a left, if the 
difference is <0.15 radians in either direction then it's not even a 
turn that I care to mention, ....

But I'm sure someone has developed and documented more of the math here, 
beyond these first steps. I'm sure I'll be asking a few questions along 
these lines, in a few weeks when I get to that phase.

-- 
Greg Allensworth, Web GIS Developer
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