CODEWITHSUNDEEP
apigoogle-maps
thiswayup
thiswayup

Reputation: 2077

working out distances between two points using google maps api?

Is it possible to send two lat long points to google to calculate the distance between the two?

Upvotes: 3

Views: 19379

Answers (8)

CRice
CRice

Reputation: 12567

And the distance cal in c#:

// this returns the distance in miles. for km multiply result: * 1.609344
public static double CalculateDistance(double lat1, double lon1, double lat2, double lon2)
{
    double t = lon1 - lon2;
    double distance = Math.Sin(Degree2Radius(lat1)) * Math.Sin(Degree2Radius(lat2)) + Math.Cos(Degree2Radius(lat1)) * Math.Cos(Degree2Radius(lat2)) * Math.Cos(Degree2Radius(t));
    distance = Math.Acos(distance);
    distance = Radius2Degree(distance);
    distance = distance * 60 * 1.1515;

    return distance;
}

private static double Degree2Radius(double deg)
{
    return (deg * Math.PI / 180.0);
}

private static double Radius2Degree(double rad)
{
    return rad / Math.PI * 180.0;
}

Upvotes: 3

SunnyD
SunnyD

Reputation: 280

If you're looking to use the v3 google maps API, here is a function I use: Note: you must add &libraries=geometry to your script source

<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false&libraries=geometry"></script>

Now the function:

//calculates distance between two points in km's
function calcDistance(p1, p2){
  return (google.maps.geometry.spherical.computeDistanceBetween(p1, p2) / 1000).toFixed(2);
}

Upvotes: 10

thiswayup
thiswayup

Reputation: 2077

there is a handy function

http://code.google.com/apis/maps/documentation/reference.html#GLatLng.distanceFrom

basically create 2 GlatLng objects then use the above method

Upvotes: 0

Brian
Brian

Reputation:

If you just want to get the distance as a number, try something like this.

function InitDistances() {
    var startLocation = new GLatLng(startLat, startLon);
    var endLocation = new GLatLng(endLat, endLon);
    var dist = startLocation .distanceFrom(endLocation);

    // Convert distance to miles with two decimal points precision
    return (dist / 1609.344).toFixed(2);
}

Upvotes: 0

Mark
Mark

Reputation: 6306

No, but you can use Vincenty's formula, which models the shape of the Earth. It's available in Javascript here.

A quite easy to parse web page is (e.g.): http://boulter.com/gps/distance/?from=51.5329855+-0.1303506&to=40.757584+-73.985642&units=m

For people who only want a quick measure of distance, check out this gadget. However, it only uses the great circle calculation.

As Rob notes, Google have added it, but they still only use the great circle formula, which can be inaccurate by 1/300.

Upvotes: 2

Rob
Rob

Reputation: 1708

Yes google can do this

google api docs

here's a piece of java script that get's the distance in km's for two points

function initialize() {
      if (GBrowserIsCompatible()) {
          map = new GMap2(document.getElementById("map_canvas"));
          map.setCenter(new GLatLng(52.6345701, -1.1294433), 13);
          map.addControl(new GLargeMapControl());          
          map.addControl(new GMapTypeControl());
          geocoder = new GClientGeocoder();

          // NR14 7PZ
          var loc1 = new GLatLng(52.5773139, 1.3712427);
          // NR32 1TB
          var loc2 = new GLatLng(52.4788314, 1.7577444);          
          alert(loc2.distanceFrom(loc1) / 1000);
      }
    }

Upvotes: 3

Fortyrunner
Fortyrunner

Reputation: 12792

Its been many years since I did this but you could use the Great Circle Distance

Upvotes: 0

Philip Morton
Philip Morton

Reputation: 131999

What you're after is the Haversine formula. You don't need Google Maps to do this, you can work it out separately. There's a script to do this (in JavaScript) here.

Upvotes: 7

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