Yes, that is something very similar to what I need to do, I already wrote a php code to check angels and slopes, but it was not accurate, it was more life "if else" code, I check the longlat for current segment with longlat for the previous one, I guess you didn't use the database for direction calculation(except for routing) am I right? Isn't steps 3 and 4 depends on your angel calculations?
I have the roads with two different languages, a road map like anyother road map I guess. On Tue, Dec 30, 2008 at 3:17 AM, Stephen Woodbridge <[email protected] > wrote: > bdair2002 wrote: > >> Hello, >> I am developing an application using Pgrouting with Postgis data, >> everything >> is fine, but now I am looking to do something like Google directions >> guide, >> where it tells you turn left or right, I am wondering if this feature is a >> built-in feature in Pgrouting or Postgis. >> >> Regards >> > > No this is not a feature that is part of either. > > I have implemented a directions explicator, but it is somewhat specific to > the data that you have, as you need to know what column(s) contain the road > names, if you have signage information then you need to know how to link to > that. If you want to be able to explicate in multiple languages, then you > probably need to consider supporting multiple languages each in a separate > table the you can select from when you generate the languages. > > The algorithm is pretty straight forward as the you currently get a list of > segments that make up the route. Then you need to: > > analyze each segment and > 1) check to see if you want to join it with the previous segment because > the road name matches > 2) check the angle that it makes with the last segment to determine right, > left, straightness of turn > 3) compute the compass heading for the segment > 4) determine if you have signage > 5) based on these, determine if you are read to explicate and which > predefined instruction you need to explicate an instruction > 6) loop through all segments > > For a demo of this you can try: > http://imaptools.com/leaddog/routing/dd.html > > Zoom into a city in one of the yellow areas, set a start and end point and > click [calculate route] button. The driving directions should show below the > button if it was successful, be patience the routing is running on a 333MHz > box. > > -Steve > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users >
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