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/


当前回答

我试着通过命名变量让代码更容易理解, 我希望这能有所帮助

function getDistanceFromLatLonInKm(point1, point2) {

  const [lat1, lon1] = point1;
  const [lat2, lon2] = point2;
  const earthRadius = 6371;
  const dLat = convertDegToRad(lat2 - lat1);
  const dLon = convertDegToRad(lon2 - lon1);
  const squarehalfChordLength =
    Math.sin(dLat / 2) * Math.sin(dLat / 2) +
    Math.cos(convertDegToRad(lat1)) * Math.cos(convertDegToRad(lat2)) *
    Math.sin(dLon / 2) * Math.sin(dLon / 2);

  const angularDistance = 2 * Math.atan2(Math.sqrt(squarehalfChordLength), Math.sqrt(1 - squarehalfChordLength));
  const distance = earthRadius * angularDistance;
  return distance;

}

其他回答

你也可以使用一个模块:

安装:

$ npm install geolib

用法:

import { getDistance } from 'geolib'

const distance = getDistance(
    { latitude: 51.5103, longitude: 7.49347 },
    { latitude: "51° 31' N", longitude: "7° 28' E" }
)

console.log(distance)

文档:https://www.npmjs.com/package/geolib

用javascript计算两点之间的距离

function distance(lat1, lon1, lat2, lon2, unit) {
        var radlat1 = Math.PI * lat1/180
        var radlat2 = Math.PI * lat2/180
        var theta = lon1-lon2
        var radtheta = Math.PI * theta/180
        var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
        dist = Math.acos(dist)
        dist = dist * 180/Math.PI
        dist = dist * 60 * 1.1515
        if (unit=="K") { dist = dist * 1.609344 }
        if (unit=="N") { dist = dist * 0.8684 }
        return dist
}

要了解更多细节,请参考这个:参考链接

谷歌的答案

https://cloud.google.com/blog/products/maps-platform/how-calculate-distances-map-maps-javascript-api

支票由三部分组成。

https://www.distancefromto.net/

static distance({ x: x1, y: y1 }, { x: x2, y: y2 }) {
    function toRadians(value) {
        return value * Math.PI / 180
    }

    var R = 6371.0710
    var rlat1 = toRadians(x1) // Convert degrees to radians
    var rlat2 = toRadians(x2) // Convert degrees to radians
    var difflat = rlat2 - rlat1 // Radian difference (latitudes)
    var difflon = toRadians(y2 - y1) // Radian difference (longitudes)
    return 2 * R * Math.asin(Math.sqrt(Math.sin(difflat / 2) * Math.sin(difflat / 2) + Math.cos(rlat1) * Math.cos(rlat2) * Math.sin(difflon / 2) * Math.sin(difflon / 2)))
}

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});
       }
      }
    });
});
}

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;
}