LSH-Hadoop is a project mainly written in JAVA and SHELL, it's free.
Implementation of Tyler Neylon's Locality-Specific Hash based on simplex tesselations
This project implements a new Locality-Specific Hashing technique for nearest-neighbor problems. http://en.wikipedia.org/wiki/Locality_sensitive_hashing http://en.wikipedia.org/wiki/Nearest_neighbor_search
This paper explains the theory of this implementation: Abstract: http://www.sciweavers.org/publications/locality-sensitive-hash-real-vectors
Full paper: http://siam.org/proceedings/soda/2010/SODA10_094_neylont.pdf
The code for the LSH algorithm is all courtesy of examples and explanation from Tyler.
The project has three parts: lsh.ortho: the core implementation lsh.solr: Solr "reprocessor": download all docs, find neighbors, upload Map/reduce assistance for Solr doc m/r jobs Contains an M/R algorithm that adds corners to all documents. Both are tested with NY State cinema location data. lsh.hadoop: map/reduce wrapper. side utility: Hadoop file reader which parses input csv lines and rearranges them.
The core insight is to use equilateral triangles instead of squares to round off locations. That's it.