Is it possible to send two lat long points to google to calculate the distance between the two?
8 Answers
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);
}
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.
Yes google can do this
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); } }
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;
}
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.
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);
}
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
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This is for version 2 of the API - do you know if a similar thing exists in V3?– RachelMay 21, 2010 at 14:42
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not that I know of but I guess the closest thing is using the route planner and getting the distance from that May 25, 2010 at 10:59