How to calculate the distance between two latitude and longitude

Question

I'm trying to calculate the distance between Vancouver and Toronto using their latitude and longitudes. I'm using haversine formula. I'm expecting a distance of around 4390 km. Can someone tell me what mistake I'm making. Here is my code:

<!DOCTYPE html> 
<html> 
<head> 
<title></title>
</head>
<body onload="getDistance()">
<script>
    // Convert Degress to Radians
    function Deg2Rad( deg ) {
       return deg * Math.PI / 180;
    }

    function getDistance()
    {       
        //Toronto Latitude  43.74 and longitude  -79.37
        //Vancouver Latitude  49.25 and longitude  -123.12
        lat1 = Deg2Rad(43.74); 
        lat2 = Deg2Rad(49.25); 
        lon1 = Deg2Rad(-79.37); 
        lon2 = Deg2Rad(-123.12);
        latDiff = lat2-lat1;
        lonDiff = lon2-lon1;
        var R = 6371000; // metres
        var φ1 = lat1;
        var φ2 = lat2;
        var Δφ = Deg2Rad(latDiff);
        var Δλ = Deg2Rad(lonDiff);

        var a = Math.sin(Δφ/2) * Math.sin(Δφ/2) +
                Math.cos(φ1) * Math.cos(φ2) *
                Math.sin(Δλ/2) * Math.sin(Δλ/2);
        var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));

        var d = R * c;
        alert('d: ' + d);

        var dist = Math.acos( Math.sin(φ1)*Math.sin(φ2) + Math.cos(φ1)*Math.cos(φ2) * Math.cos(Δλ) ) * R;
        alert('dist: ' + dist);
    }       
 </script>
 </body>
 </html>

When I run this code, I get quite different numbers.

Possible duplicate of [Calculate distance between two latitude-longitude points? (Haversine formula)](http://stackoverflow.com/questions/27928/calculate-distance-between-two-latitude-longitude-points-haversine-formula) — Teemu, Mar 11 '16 at 20:23
Result of the above code doesn't produce correct numbers and I need some help. I know Haversine question has been asked here before. — , Mar 11 '16 at 20:34

dmgig · Accepted Answer · 2016-03-11T20:46:05.777

1

I think you should expect more like 3358km. http://www.distancefromto.net/distance-from/Toronto/to/Vancouver

Here is a fiddle with the correct result: https://jsfiddle.net/Lk1du2L1/

And in that case, you'll be correct if you'd remove your deg2rad form your secondary results - you're doing it too often:

 <!DOCTYPE html> 
<html> 
<head> 
<title></title>
</head>
<body onload="getDistance()">
<script>
    // Convert Degress to Radians
    function Deg2Rad( deg ) {
       return deg * Math.PI / 180;
    }

    function getDistance()
    {       
        //Toronto Latitude  43.74 and longitude  -79.37
        //Vancouver Latitude  49.25 and longitude  -123.12
        lat1 = Deg2Rad(43.74); 
        lat2 = Deg2Rad(49.25); 
        lon1 = Deg2Rad(-79.37); 
        lon2 = Deg2Rad(-123.12);
        latDiff = lat2-lat1;
        lonDiff = lon2-lon1;
        var R = 6371000; // metres
        var φ1 = lat1;
        var φ2 = lat2;
        var Δφ = latDiff;
        var Δλ = lonDiff;

        var a = Math.sin(Δφ/2) * Math.sin(Δφ/2) +
                Math.cos(φ1) * Math.cos(φ2) *
                Math.sin(Δλ/2) * Math.sin(Δλ/2);
        var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));

        var d = R * c;
        alert('d: ' + d);

        var dist = Math.acos( Math.sin(φ1)*Math.sin(φ2) + Math.cos(φ1)*Math.cos(φ2) * Math.cos(Δλ) ) * R;
        alert('dist: ' + dist);
    }       
 </script>
 </body>
 </html>

edited Mar 11 '16 at 20:46

answered Mar 11 '16 at 20:29

dmgig

4,400
5
36
47

I know, I can't find the mistake I'm making in the code. When I run the code, I get quite a different number 85568.6616. – Mar 11 '16 at 20:37
look at the code I posted. When I run you code with those changes, I get the correct distance: `d: 3355945.3482` – dmgig Mar 11 '16 at 20:38
You already converted deg2rad when you created your lat1 & lat2 etc variables. When you do it again, you are changing your values and getting the incorrect `85568.661` number. – dmgig Mar 11 '16 at 20:40
I changed my code. Removed the duplicate and now I get dist: 615456.6054867743 which doesn't look correct either. – Mar 11 '16 at 20:45
I reposted the whole code. When I run this, I get `3355945.3482` – dmgig Mar 11 '16 at 20:46
when i added this code in my angularjs project i am getting illegal character error while compiling. – Shamseer PC May 15 '18 at 06:05
maybe it is having trouble with those greek characters? – dmgig May 15 '18 at 21:13
1

Yes greek characters are making trouble. when i replace it with the normal character it is working. – Shamseer PC May 17 '18 at 03:33

How to calculate the distance between two latitude and longitude

1 Answers1