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From Kurt Christensen <hoo...@hoodel.com>
Subject Re: Z-Curve/Hilbert Curve
Date Sat, 26 Jul 2014 12:58:28 GMT

The first thing that comes to my mind is bit shuffling. Scale and shift 
lat and lon into [0,1) ranges. That is from 0.000... to 0.111... Then, 
starting just past the decimal point, take the first lon bit (first 
since double the range of lat), then the first lat bit. Then just 
alternate, second bits, third bits, until you have as much precision as 
you like. There are discontinuities in the resulting curve, but any 
point is easy to encode and decode, and it provides a 1-dimensional sort.

I hope that helps.

Kurt

On 7/24/14 10:10 AM, THORMAN, ROBERT D wrote:
> Can anyone share a Java method to convert lat/lon (decimal degrees) to 
> Z-Curve (string)?  I need to order my geo-spatial data into lexical 
> order.
>
> v/r
> Bob Thorman
> Principal Big Data Engineer
> AT&T Big Data CoE
> 2900 W. Plano Parkway
> Plano, TX 75075
> 972-658-1714
>
>

-- 

Kurt Christensen
P.O. Box 811
Westminster, MD 21158-0811

------------------------------------------------------------------------
If you can't explain it simply, you don't understand it well enough. -- 
Albert Einstein

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