The Algorithm
From Geohashing
Revision as of 22:34, 23 May 2008 by imported>Tjtrumpet2323
This time, we did invent the algorithm!
- The current date (in yyyy-mm-dd format) and the daily opening price of the Dow Jones Industrial Average are concatenated with a hyphen and fed through the MD5 cryptographic algorithm to generate as pseudo-random string of 32 hexadecimal digits.
- If there is no opening price for the Dow, the opening price from its previous day of active trading is used instead.
- The resulting string is split into two halves of 16 hexadecimal digits.
- Each half-string is prepended with a decimal point (so as to represent a hexadecimal fraction) and is converted to a base-10 fraction.
- The resulting decimal fractions are appended to the integral (lat,lon) values of any given graticule to produce that graticule's geohash target.
Fractional hexadecimal to decimal calculation
Many online hex-to-dec converters do not support hexadecimal fractions. Here is one that does:
