API to calculate distances

General Programming
1

I have a Xojo 2019 3.1 desktop app on Mac 10.14.6 and need something like a google maps API to calculate the distance between 2 addresses. Do not need to display any maps or other graphics.

Any Suggestions???

2

Why not subscribe to the Google Maps API?
and distance? driving distance or as the crow flies?

1 Like
3

You can also look in TOF as something similar has been discussed there.

1 Like
4

This is why I asked “driving” or “as the crow flys”

Great Circle gives the “straight” distance between 2 GPS coordinates.

I had a very accurate formula for this that I used to locate all the addresses within X miles of a known hospital… but no longer have access to the source

5

If you happened to have or could get the latitude and longitude of the two addresses you could convert the php could I use to calculate the distances in miles to Xojo:

$r = 6371; // add e3 for metres
//degrees * 0.01745329252 = radians
$d1 = deg2rad($the_latitude[$i]);
$d2 = deg2rad($the_latitude[$j]);
$clat = deg2rad($the_latitude[$j] - $the_latitude[$i]);
$clong = deg2rad($the_longitude[$j] - $the_longitude[$i]);
$a = sin($clat / 2) * sin($clat / 2) + cos($d1) * cos($d2) * sin($clong /2) * sin($clong/2);
$c = 2 * atan2(sqrt($a), sqrt(1 - $a));
$d = round($r * $c * 0.621371);

Can’t remember where I Googled this from but when I use this for cities, it matches very well with Google results for “distance between a and b”.