Failed Experiment: Memory Efficient Spatial Hashtable

The Background of my Idea The idea is to use a hash table for points (aka HashMap in Java) and try to implement neighbor searches. First of all you’ll need to understand what a spatial key is. Here you can read the details, but in short it is a binary Geohash where you avoid the memory … Continue reading

How I found the Googloson and why it has negative Energy

I have finally found the Googloson with my self-made Small Googtron Collidor (SGC) – I even had the time to make a photo of it to show you that it is not a fake (see below). Everyone will say I’ve gimped that, but no, I didn’t. Really. I have developed a theoretical proof of the existence of … Continue reading

Spatial Keys – Memory Efficient Geohashes

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 … Continue reading

Free Online Graph Theory Books and Resources

A link compilation of some Hackernews and Stackoverflow posts and a longish personal investigation. The DaMN book and its companion book Graph Theory with Applications, J.A. Bondy and U.S.R. Murty Graph Theory, Reinhard Diestel Graph Theory Tutorials Digraphs: Theory, Algorithms and Applications, 1st Edition Wikipedia – Graph Algorithms Algorithms and Complexity, Herbert S. Wilf Lecture … Continue reading

Rage Against the Android #eclipse

Developing Android applications on Linux with Eclipse sometimes can get really ugly. Sadly neither NetBeans which has a really nice Android plugin, but cannot execute a single test nor IDEA can rescue me or make me switching :( but probably they wouldn’t rescue me due to problems of Android development kit itself – I’m not … Continue reading