[gdal-dev] OGRGeometry Distance

[Mateusz Loskot]

Christopher Barker wrote:
> Yilmaz Arslanoglu wrote:
>> I wanted to compute the distance between two points,
> 
> you need to be clear by what you mean here: I suspect you mean:
> 
> "The shortest distance between two points following the surface of the 
> earth"
> 
> In which case, what you are looking for is referred to as the geodesic 
> distance:
> 
> http://www.vterrain.org/Misc/distance.html
> 
> To do this accurately (and you may not need much accuracy!) on an 
> ellipsoid requires a fair bit of math. I don't know if it's built in to 
> OGR or PROJ at this point, but there are a few libraries out that that 
> do it, including Gerald I. Evenden's "geodesic" lib, which can be found 
> here:
> 
> http://home.comcast.net/~gevenden56/geodesy/project/

Here is another interesting article on that subject:

http://www.codeguru.com/Cpp/Cpp/algorithms/general/article.php/c5115/

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net