获取两坐标之间距离

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    <body class="beg-login-bg">
        
    <script>
        window.onload=function(){
            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;

            }
            /**

             * approx distance between two points on earth ellipsoid

             * @param {Object} lat1

             * @param {Object} lng1

             * @param {Object} lat2

             * @param {Object} lng2

             */

            function getFlatternDistance(lat1,lng1,lat2,lng2){

                var f = getRad((lat1 + lat2)/2);

                var g = getRad((lat1 - lat2)/2);

                var l = getRad((lng1 - lng2)/2);

                

                var sg = Math.sin(g);

                var sl = Math.sin(l);

                var sf = Math.sin(f);

                

                var s,c,w,r,d,h1,h2;

                var a = EARTH_RADIUS;

                var fl = 1/298.257;

                

                sg = sg*sg;

                sl = sl*sl;

                sf = sf*sf;

                

                s = sg*(1-sl) + (1-sf)*sl;

                c = (1-sg)*(1-sl) + sf*sl;

                

                w = Math.atan(Math.sqrt(s/c));

                r = Math.sqrt(s*c)/w;

                d = 2*w*a;

                h1 = (3*r -1)/2/c;

                h2 = (3*r +1)/2/s;

                

                return d*(1 + fl*(h1*sf*(1-sg) - h2*(1-sf)*sg));

            }
            console.log(getGreatCircleDistance(39.87945682,116.64095684,39.91406638,116.60629272))
            console.log(getFlatternDistance(39.87945682,116.64095684,39.91406638,116.60629272)) 
        }
            
        </script>
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posted @ 2018-04-26 14:47  王汉炎  阅读(619)  评论(0编辑  收藏