[SGVLUG] Distance between two locations

[Peter Fogg]

Thanks for the responses, guys! My requirement is for great circle 
distance between locations. There is code out there for calculating the 
required distance but it requires that the longitude and latitude of 
the end-points be manually entered. This will, of course, work.

However, the site is a MySpace-type site in which a a member can search 
for other members within a given distance. The distance required is 
great circle distance between addresses. BTW, within the Continental 
USA.

I am hoping that I can contact someone with experience this capability 
in a Web site.

Peter -

On Aug 3, 2007, at 5:19 PM, Emerson, Tom (*IC) wrote:

>> -----Original Message----- Of Peter Fogg
>>
>> The site that I am developing requires the ability to calculate the
>> distance between to locations.
>
> Is this for distance "as the crow flies", or what it would actually 
> take
> to "drive" from point A to point B?
>
> Straight-line distance is a simple formula [potentially made more
> difficult by converting polar coordinates into cartesian].  Would
> relative altitudes between the two locations be part of the problem?
> (for example, the distance from one side to the other of a cliff might
> be only 10 feet horizontally, but a couple thousand in the vertical
> direction... ;) )
>
> "driving distance" would have to take into account one-way roads,
> construction/blockages, traffic patterns (if you're trying to determine
> "fastest" route, which will not be the "shortest" if traffic comes to a
> standstill on the short route...)  This type of problem would indeed
> have to have database of some sort for location of intersections,
> blockages/one-way, etc.
>