我目前正在使用下面的功能，它不能正常工作。根据谷歌Maps，这些坐标之间的距离(从59.3293371,13.4877472到59.3225525,13.4619422)是2.2公里，而函数返回1.6公里。我怎样才能使这个函数返回正确的距离?
function getDistanceFromLatLonInKm(lat1, lon1, lat2, lon2) {
var R = 6371; // Radius of the earth in km
var dLat = deg2rad(lat2-lat1); // deg2rad below
var dLon = deg2rad(lon2-lon1);
var a =
Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) *
Math.sin(dLon/2) * Math.sin(dLon/2)
;
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c; // Distance in km
return d;
}
function deg2rad(deg) {
return deg * (Math.PI/180)
}
jsFiddle: http://jsfiddle.net/edgren/gAHJB/
如前所述，函数是计算到目标点的直线距离。如果你想要行车距离/路线，你可以使用谷歌地图距离矩阵服务:
getDrivingDistanceBetweenTwoLatLong(origin, destination) {
return new Observable(subscriber => {
let service = new google.maps.DistanceMatrixService();
service.getDistanceMatrix(
{
origins: [new google.maps.LatLng(origin.lat, origin.long)],
destinations: [new google.maps.LatLng(destination.lat, destination.long)],
travelMode: 'DRIVING'
}, (response, status) => {
if (status !== google.maps.DistanceMatrixStatus.OK) {
console.log('Error:', status);
subscriber.error({error: status, status: status});
} else {
console.log(response);
try {
let valueInMeters = response.rows[0].elements[0].distance.value;
let valueInKms = valueInMeters / 1000;
subscriber.next(valueInKms);
subscriber.complete();
}
catch(error) {
subscriber.error({error: error, status: status});
}
}
});
});
}
我以前写过一个类似的方程-测试了它，也得到了1.6 km。
你的谷歌地图显示了驾驶距离。
你的函数是按照直线距离计算的。
alert(calcCrow(59.3293371,13.4877472,59.3225525,13.4619422).toFixed(1));
//This function takes in latitude and longitude of two location and returns the distance between them as the crow flies (in km)
function calcCrow(lat1, lon1, lat2, lon2)
{
var R = 6371; // km
var dLat = toRad(lat2-lat1);
var dLon = toRad(lon2-lon1);
var lat1 = toRad(lat1);
var lat2 = toRad(lat2);
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
return d;
}
// Converts numeric degrees to radians
function toRad(Value)
{
return Value * Math.PI / 180;
}
Derek的解决方案对我来说很好，我只是简单地将其转换为PHP，希望它能帮助到一些人!
function calcCrow($lat1, $lon1, $lat2, $lon2){
$R = 6371; // km
$dLat = toRad($lat2-$lat1);
$dLon = toRad($lon2-$lon1);
$lat1 = toRad($lat1);
$lat2 = toRad($lat2);
$a = sin($dLat/2) * sin($dLat/2) +sin($dLon/2) * sin($dLon/2) * cos($lat1) * cos($lat2);
$c = 2 * atan2(sqrt($a), sqrt(1-$a));
$d = $R * $c;
return $d;
}
// Converts numeric degrees to radians
function toRad($Value)
{
return $Value * pi() / 180;
}
为Node.JS用户添加这个。您可以使用haversine-distance模块来实现这一点，这样您就不需要自己处理计算。更多信息请参见npm页面。
如何安装:
NPM安装——保存haversine-distance
该模块的使用方法如下:
var haversine = require("haversine-distance");
//First point in your haversine calculation
var point1 = { lat: 6.1754, lng: 106.8272 }
//Second point in your haversine calculation
var point2 = { lat: 6.1352, lng: 106.8133 }
var haversine_m = haversine(point1, point2); //Results in meters (default)
var haversine_km = haversine_m /1000; //Results in kilometers
console.log("distance (in meters): " + haversine_m + "m");
console.log("distance (in kilometers): " + haversine_km + "km");
