A couple of thoughts: - partition your data (this is what we did for processing large graphs for british columbia data). Partition into a grid if you have to ... - construct graphs at different level of detail (a common approach for navigation systems); have fine grained graphs (streets and alleys for each city); and low grained information for national highways. When finding a route you often need to load up the national highways and the streets&alleys for two cities. - make sure your builder is not holding on to too much information (it does not need to store an entire Feature for each edge getObject for example) - experiment with different graph data structures (the builder api makes this happy to try out) there is lots of academic papers (and even Knuth) on the subject - make us happy by building one of those nice disk based representations of a graph (bonus points for letting us load up graphs at different levels of detail) - or make us happy by building a graph data structure into some postgis tables - finally you can look at how oracles has done it (they have captured graphs as data structures at different levels of detail - and then implemented PSQL functions to answer common questions)
Cheers, Jody Sébastien PIAU wrote: > Hello, > > > We used Geotools (2.3.0) in order to perform route calculation. > Everything works fine with a reasonable number of streets, but when > trying to use millions of segments, our application cannot start : we > have not enough memory (i've tried with memory up to 4Gb)! > In order to accomplish route calculation we used classes inside the > "graph" package, such as graph, node, edge and so on... > Is there some bests practices to follow in order to perform route > calculation with a tremendous number of streets? > > Any help will be welcome! > > Thanks in advance, > > Sebastien > > PS: Sorry for my previous post which came in reply on Mr Milton message! > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Geotools-gt2-users mailing list > Geotools-gt2-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Geotools-gt2-users mailing list Geotools-gt2-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
