Today we’re proud to announce the first stable release of GraphHopper! After over a year of busy development we finally reached version 0.1! GraphHopper is a fast and Open Source road routing engine written in Java based on OpenStreetMap data. It handles the full planet on a 15GB server but is also scales down and […]
I’ve not blogged since a while but we are pushing Java road routing via GraphHopper to its first public release 0.1! We’re not finished yet, but have a first look and give us feedback here or in the mailing list (questions, bugs, …) so that we can release without big surprises in a few days […]
Update: With changes introduced in January 2013 you only need 1GB – live demo! In one of my last blog posts I wrote about memory efficient ways of coding Java. My conclusion was not a bright one for Java: “This time the simplicity of C++ easily beats Java, because in Java you need to operate […]
In Java land there are at least two quadtree implementations which are not yet optimal, so I though I’ll post some possibilities to tune them. Some of those possibilities are already implemented in my GraphHopper project. Quadtree What is a quadtree? Wikipedia says: “A quadtree is a tree data structure in which each internal node […]
When you are operating on geographical data you can use latitude and longitude to specify a location somewhere on earth. To look up some associated information like we do in GraphHopper for the next street or if you want to do neighborhood searches you could create R-trees, quad-trees or similar spatial data structures to make […]
