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/
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)))
}
试试这个。它在VB.net中，您需要将其转换为Javascript。此函数接受十进制分钟的参数。
Private Function calculateDistance(ByVal long1 As String, ByVal lat1 As String, ByVal long2 As String, ByVal lat2 As String) As Double
long1 = Double.Parse(long1)
lat1 = Double.Parse(lat1)
long2 = Double.Parse(long2)
lat2 = Double.Parse(lat2)
'conversion to radian
lat1 = (lat1 * 2.0 * Math.PI) / 60.0 / 360.0
long1 = (long1 * 2.0 * Math.PI) / 60.0 / 360.0
lat2 = (lat2 * 2.0 * Math.PI) / 60.0 / 360.0
long2 = (long2 * 2.0 * Math.PI) / 60.0 / 360.0
' use to different earth axis length
Dim a As Double = 6378137.0 ' Earth Major Axis (WGS84)
Dim b As Double = 6356752.3142 ' Minor Axis
Dim f As Double = (a - b) / a ' "Flattening"
Dim e As Double = 2.0 * f - f * f ' "Eccentricity"
Dim beta As Double = (a / Math.Sqrt(1.0 - e * Math.Sin(lat1) * Math.Sin(lat1)))
Dim cos As Double = Math.Cos(lat1)
Dim x As Double = beta * cos * Math.Cos(long1)
Dim y As Double = beta * cos * Math.Sin(long1)
Dim z As Double = beta * (1 - e) * Math.Sin(lat1)
beta = (a / Math.Sqrt(1.0 - e * Math.Sin(lat2) * Math.Sin(lat2)))
cos = Math.Cos(lat2)
x -= (beta * cos * Math.Cos(long2))
y -= (beta * cos * Math.Sin(long2))
z -= (beta * (1 - e) * Math.Sin(lat2))
Return Math.Sqrt((x * x) + (y * y) + (z * z))
End Function
编辑
javascript中的转换函数
function calculateDistance(lat1, long1, lat2, long2)
{
//radians
lat1 = (lat1 * 2.0 * Math.PI) / 60.0 / 360.0;
long1 = (long1 * 2.0 * Math.PI) / 60.0 / 360.0;
lat2 = (lat2 * 2.0 * Math.PI) / 60.0 / 360.0;
long2 = (long2 * 2.0 * Math.PI) / 60.0 / 360.0;
// use to different earth axis length
var a = 6378137.0; // Earth Major Axis (WGS84)
var b = 6356752.3142; // Minor Axis
var f = (a-b) / a; // "Flattening"
var e = 2.0*f - f*f; // "Eccentricity"
var beta = (a / Math.sqrt( 1.0 - e * Math.sin( lat1 ) * Math.sin( lat1 )));
var cos = Math.cos( lat1 );
var x = beta * cos * Math.cos( long1 );
var y = beta * cos * Math.sin( long1 );
var z = beta * ( 1 - e ) * Math.sin( lat1 );
beta = ( a / Math.sqrt( 1.0 - e * Math.sin( lat2 ) * Math.sin( lat2 )));
cos = Math.cos( lat2 );
x -= (beta * cos * Math.cos( long2 ));
y -= (beta * cos * Math.sin( long2 ));
z -= (beta * (1 - e) * Math.sin( lat2 ));
return (Math.sqrt( (x*x) + (y*y) + (z*z) )/1000);
}
你使用的是哈弗辛公式，它计算了当乌鸦飞行时球面上两点之间的距离。您提供的谷歌Maps链接显示距离为2.2公里，因为它不是一条直线。
Wolfram Alpha是进行地理计算的一个很好的资源，它还显示了这两点之间的距离为1.652公里。
如果您正在寻找直线距离(如crow文件)，则您的函数工作正常。如果你想要的是开车距离(或骑自行车距离、公共交通距离或步行距离)，你必须使用一个映射API(谷歌或Bing是最流行的)来获得适当的路线，其中将包括距离。
顺便提一下，谷歌Maps API在其Google . Maps .geometry.spherical命名空间(查找computeDistanceBetween)中提供了一个打包的球面距离方法。这可能比你自己卷更好(首先，它使用了更精确的地球半径值)。
对于挑剔的我们来说，我说的“直线距离”，指的是“球面上的直线”，实际上当然是一条曲线(即大圆距离)。
我在typescript和ES6中实现了这个算法
export type Coordinate = {
lat: number;
lon: number;
};
求两点之间的距离:
function getDistanceBetweenTwoPoints(cord1: Coordinate, cord2: Coordinate) {
if (cord1.lat == cord2.lat && cord1.lon == cord2.lon) {
return 0;
}
const radlat1 = (Math.PI * cord1.lat) / 180;
const radlat2 = (Math.PI * cord2.lat) / 180;
const theta = cord1.lon - cord2.lon;
const radtheta = (Math.PI * theta) / 180;
let dist =
Math.sin(radlat1) * Math.sin(radlat2) +
Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
if (dist > 1) {
dist = 1;
}
dist = Math.acos(dist);
dist = (dist * 180) / Math.PI;
dist = dist * 60 * 1.1515;
dist = dist * 1.609344; //convert miles to km
return dist;
}
获取坐标数组之间的距离
export function getTotalDistance(coordinates: Coordinate[]) {
coordinates = coordinates.filter((cord) => {
if (cord.lat && cord.lon) {
return true;
}
});
let totalDistance = 0;
if (!coordinates) {
return 0;
}
if (coordinates.length < 2) {
return 0;
}
for (let i = 0; i < coordinates.length - 2; i++) {
if (
!coordinates[i].lon ||
!coordinates[i].lat ||
!coordinates[i + 1].lon ||
!coordinates[i + 1].lat
) {
totalDistance = totalDistance;
}
totalDistance =
totalDistance +
getDistanceBetweenTwoPoints(coordinates[i], coordinates[i + 1]);
}
return totalDistance.toFixed(2);
}
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;
}
