On Fri, Apr 16, 2010 at 12:56 PM, Jens Müller <[email protected]> wrote: > As you have probably looked into that in quite some detail: Is it > necessary to do precomputations for every edge length function to be > used (e.g., car, pedestrian, mountain bike, racing bike, $userdefined)? > Or can the algorithm deal with small modifications?
The current implementation can only deal with fixed edge length, thus you'd have to precompute a Contraction Hierarchy for every objective function you'd like to supply. While dealing with linear combinations of objective functions is possible [1], it is quite complex. However, the precomputation of Contraction Hierarchies is quite fast and techniques used for Mobile Contraction Hierarchies [2] can be used to avoid loading the whole Contraction Hierarchy into memory during route computations. This makes it possible for a single server to provide a larger amount of objective functions while still maintaining fast query times. Greetings Chris [1] http://algo2.iti.kit.edu/english/1440.php [2] http://algo2.iti.kit.edu/english/1187.php _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
