Google Maps Api v3 - find nearest markers

Questions

When i click on map, which will be best way to find nearest marker or markers? is there some functions in api that will help me to do that?

it s google map api v3.

Answers

First you have to add the eventlistener

google.maps.event.addListener(map,  click , find_closest_marker);

http://en.wikipedia.org/wiki/Haversine_formula http://en.wikipedia.org/wiki/Haversine_formula

function rad(x) {return x*Math.PI/180;}
function find_closest_marker( event ) {
    var lat = event.latLng.lat();
    var lng = event.latLng.lng();
    var R = 6371; // radius of earth in km
    var distances = [];
    var closest = -1;
    for( i=0;i<map.markers.length; i++ ) {
        var mlat = map.markers[i].position.lat();
        var mlng = map.markers[i].position.lng();
        var dLat  = rad(mlat - lat);
        var dLong = rad(mlng - lng);
        var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
            Math.cos(rad(lat)) * Math.cos(rad(lat)) * Math.sin(dLong/2) * Math.sin(dLong/2);
        var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
        var d = R * c;
        distances[i] = d;
        if ( closest == -1 || d < distances[closest] ) {
            closest = i;
        }
    }

    alert(map.markers[closest].title);
}

This keeps track of the closest markers and alerts its title.

I have my markers as an array on my map object

Source

License : cc by-sa 3.0

http://stackoverflow.com/questions/4057665/google-maps-api-v3-find-nearest-markers

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