Lance, have you figured out what the issue is?
Anyone know if this is a haversine limitation, or a bug?
-Yonik
http://lucenerevolution.org Lucene/Solr Conference, Boston Oct 7-8
On Wed, Aug 18, 2010 at 1:54 AM, Lance Norskog goks...@gmail.com wrote:
The Haversine formula in
It might have something to do with the source data and its spatial reference
system. For example, if the data is in WGS84 then the haversine (great
circle) distance precision gets worse the farther away two cities are from
each other or for particular regions (e.g. further away from equator).
I copied a different formulation out of the Wikipedia article on
Haversine. It's the same idea as in DistanceUtils, but turned inside
out with cosines instead of sines. It gives exactly the same results.
This is not with source data, just using round numbers in the
latitude/longitude space.
I do
On Fri, Aug 20, 2010 at 11:05 PM, Lance Norskog goks...@gmail.com wrote:
are latitudes equidistant on the surface of the sphere?
Yes - each degree of latitude is ~69 miles.
There is also a slight variation due to the earth not being a perfect sphere.
-Yonik
http://lucenerevolution.org
The Haversine formula in o.a.s.s.f.d.DistanceUtils.java gives these
results for a 0.1 degree difference in miles:
equator horizontal 0.1 deg: lat/lon 0.0/0.0 - 396.320504
equator vertical 0.1 deg: lat/lon 0.0/0.0 - 396.320504
NYC horizontal 0.1 deg: lat/lon -72.0/0.0
