Geohash
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Geohash is a way to encode latitude and longitude coordinates into a short string, allowing locations to be stored, searched, and analyzed efficiently. The presenter will discuss how geohashing works by subdividing space into grid "buckets" and degrading precision with shorter hashes. He will explain how his company uses geohashing to analyze visitors from different locations and check for duplicates more efficiently than with raw latitude/longitude or large addresses.
Geohash
- 1. Geohash {lat/lon string} Python Developer Nepal Meetup #6 March 19, 2015
- 2. Who am I? Narayan Kandel Developer at nLocate (Python/Django) Previously Java Developer at Deerwalk
- 3. What I Will Cover 1. Our requirements 2. What is a geohash? 3. How does it work? 4. How we use it?
- 4. Our Requirement Analyze visitor from different location different data 1. business data 2. user generated log Duplication Check
- 5. What is Geohashing Simple way to encode lat/lng into a string Compact string encoding of geographic coordinate with arbitrary precision Kathmandu - tuut, Chitwan - tuuj Invented by Gustavo Niemeyer for geohash.org Available in public domain http://en.wikipedia.org/wiki/geohash/
- 6. Why do we need it when we have lat/lon Big address of venue ABC road Lalitpur Sub-Municipality -12, Kupondole Lalitpur, Bagmati Nepal Complicated Lat/Long {27.6830282799,85.3180309269}
- 7. Subdivides space into "buckets" of grid shape Doesn't really represent a point, rather a bounding area in which the point is present Hierarchical spatial structure with gradual degradation Longer the geohash Smaller the area snap taken from geohash.gofreerange.com
- 8. How does it work?
- 9. How does it work?
- 10. Mapping 5 bits (25 ) = 32 alpha-numeric 1-9 b-z except a, i, l, o *http://en.wikipedia.org/wiki/Geohash
- 11. How does it work?... demo snap taken from geohash.gofreerange.com
- 12. Lets come to our problem Analyze visitor from different location Method 1: Polygon
- 13. Analyze visitor from different location ... Method 2 Geohashing Prefix Matching
- 14. Other Area Where we used it To find duplicate Spot - O(n2 )
- 15. Other Application twitter - location based tweet count/find trend on particular location flickr/instagram - find location based photo with area selection on number of prefix alerter system at telecommunication (integration of hardware location + customer complain location) and many more...
- 16. References Geohash - http://en.wikipedia.org/wiki/Geohash
- 17. Thank You twitter: @dearnarayan email: narayan@nlocate.com