js计算两点之间的经纬度

系统管理员 2022-07-15 14:21 320阅读 0赞

<!DOCTYPE html>
    <html>
    <head>
        <meta charset="utf-8">
    	<title></title>
    </head>
    <body οnlοad="load();">
    纬度1<input id="lat1" type="text" name="">
    经度1 <input id="lng1" type="text" name="">
    纬度2<input id="lat2" type="text" name="">
    经度2 <input id="lng2" type="text" name="">
    <button id="calc" type="button">计算</button>
    </body>
    <script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
    <script type="text/javascript">
    	function load() {
    		$("#calc").click(function() {
    			var lat1 = parseFloat($("#lat1").val());
    			var lng1 = parseFloat($("#lng1").val());
    			var lat2 = parseFloat($("#lat2").val());
    			var lng2 = parseFloat($("#lng2").val());
    
    			alert(getGreatCircleDistance(lat1,lng1,lat2,lng2));
    		});
    	}
    
    
    	var EARTH_RADIUS = 6378137.0;    //单位M
        var PI = Math.PI;
        
        function getRad(d){
            return d*PI/180.0;
        }
        
        /**
         * caculate the great circle distance
         * @param {Object} lat1
         * @param {Object} lng1
         * @param {Object} lat2
         * @param {Object} lng2
         */
        function getGreatCircleDistance(lat1,lng1,lat2,lng2){
            var radLat1 = getRad(lat1);
            var radLat2 = getRad(lat2);
            
            var a = radLat1 - radLat2;
            var b = getRad(lng1) - getRad(lng2);
            
            var s = 2*Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) + Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2)));
            s = s*EARTH_RADIUS;
            s = Math.round(s*10000)/10000.0;
                    
            return s;
        }
    	
    
    </script>
    </html>