Re: earthdistance is not giving correct results.

Maybe it would work with the right long & lat...
try
Protland OR -122.67555, 45.51184
Seattle WA -122.32956, 47.60342

Also, do not forget that it is the line distance not the driving distance.




Michael Fuhr wrote:
> On Sat, Oct 02, 2004 at 07:09:25PM -0400, Tom Lane wrote:
>
>>mike cox <mikecoxlinux@yahoo.com> writes:
>>
>>>The distance from Portland to Seattle is not 128862
>>>miles.
>>
>>How about 128.8 kilometers?  The earthdistance docs say it's in meters
>>unless you've redefined the base unit.
>
>
> 128.8 kilometers is about 80 miles; the distance from Portland to
> Seattle is more like 150 miles.
>
>
>>>earth_distance(ll_to_earth('122.55688','45.513746'),ll_to_earth('122.396357','47.648845'));
>
>
> I haven't played with earthdistance, but I'd guess that the arguments
> to ll_to_earth should be (latitude, longitude) instead of (longitude,
> latitude).
>
> Here are some queries from my own implementation of the haversine
> function, which is another way to measure distances on a sphere:
>
> => select haversine(122.55688, 45.513746, 122.396357, 47.648845);
>     haversine
> ------------------
>  79.9258188445352
>
> That distance is miles, which is almost exactly equivalent to the
> 128.8km figure from earth_distance().  Correcting the order of the
> arguments gives this:
>
> => select haversine(45.513746, 122.55688, 47.648845, 122.396357);
>     haversine
> ------------------
>  147.614987754694
>
> That's more like the true distance in miles between Portland and
> Seattle
>