Javascript 如何计算一个点与另一个点之间一定距离的距离？
为了在地图上画一个圆，我有一个中心玻璃（a）和一个半径（r），单位为米 下面是一张图表：Javascript 如何计算一个点与另一个点之间一定距离的距离？,javascript,google-maps,Javascript,Google Maps,为了在地图上画一个圆，我有一个中心玻璃（a）和一个半径（r），单位为米 下面是一张图表： ----------- --/ \-- -/ \- / \ / \ / r \ | *-------------* \
-----------
--/ \--
-/ \-
/ \
/ \
/ r \
| *-------------*
\ A / B
\ /
\ /
-\ /-
--\ /--
-----------
使用GLatLng.distanceFrom（）方法在给定A和B时获取半径是很简单的，但是用另一种方法却不是这样。似乎我需要做一些更重的计算。这个问题的答案以及更多的答案可以在这里找到：我们需要一种方法，在给定方位和从源点移动的距离时返回目标点。幸运的是，Chris Vensity在上有一个非常好的JavaScript实现 以下内容适用于本课程： 您只需按如下方式使用它：
var pointA = new google.maps.LatLng(25.48, -71.26);
var radiusInKm = 10;
var pointB = pointA.destinationPoint(90, radiusInKm);
pointA.destinationPoint（90，半径）的屏幕截图
如果您在地球表面上两个lat/lng点之间的距离之后，您可以在此处找到javascript：
这与android API在android.location.location:：distance to
您可以轻松地将代码从javascript转换为java
如果要计算给定起点、方位和距离的终点，
那么你需要这个方法：
以下是java中的公式：
public class LatLngUtils {
/**
* @param lat1
* Initial latitude
* @param lon1
* Initial longitude
* @param lat2
* destination latitude
* @param lon2
* destination longitude
* @param results
* To be populated with the distance, initial bearing and final
* bearing
*/
public static void computeDistanceAndBearing(double lat1, double lon1,
double lat2, double lon2, double results[]) {
// Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
// using the "Inverse Formula" (section 4)
int MAXITERS = 20;
// Convert lat/long to radians
lat1 *= Math.PI / 180.0;
lat2 *= Math.PI / 180.0;
lon1 *= Math.PI / 180.0;
lon2 *= Math.PI / 180.0;
double a = 6378137.0; // WGS84 major axis
double b = 6356752.3142; // WGS84 semi-major axis
double f = (a - b) / a;
double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);
double L = lon2 - lon1;
double A = 0.0;
double U1 = Math.atan((1.0 - f) * Math.tan(lat1));
double U2 = Math.atan((1.0 - f) * Math.tan(lat2));
double cosU1 = Math.cos(U1);
double cosU2 = Math.cos(U2);
double sinU1 = Math.sin(U1);
double sinU2 = Math.sin(U2);
double cosU1cosU2 = cosU1 * cosU2;
double sinU1sinU2 = sinU1 * sinU2;
double sigma = 0.0;
double deltaSigma = 0.0;
double cosSqAlpha = 0.0;
double cos2SM = 0.0;
double cosSigma = 0.0;
double sinSigma = 0.0;
double cosLambda = 0.0;
double sinLambda = 0.0;
double lambda = L; // initial guess
for (int iter = 0; iter < MAXITERS; iter++) {
double lambdaOrig = lambda;
cosLambda = Math.cos(lambda);
sinLambda = Math.sin(lambda);
double t1 = cosU2 * sinLambda;
double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
double sinSqSigma = t1 * t1 + t2 * t2; // (14)
sinSigma = Math.sqrt(sinSqSigma);
cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
sigma = Math.atan2(sinSigma, cosSigma); // (16)
double sinAlpha = (sinSigma == 0) ? 0.0 : cosU1cosU2 * sinLambda
/ sinSigma; // (17)
cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
cos2SM = (cosSqAlpha == 0) ? 0.0 : cosSigma - 2.0 * sinU1sinU2
/ cosSqAlpha; // (18)
double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
A = 1 + (uSquared / 16384.0) * // (3)
(4096.0 + uSquared * (-768 + uSquared * (320.0 - 175.0 * uSquared)));
double B = (uSquared / 1024.0) * // (4)
(256.0 + uSquared * (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
double C = (f / 16.0) * cosSqAlpha * (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
double cos2SMSq = cos2SM * cos2SM;
deltaSigma = B
* sinSigma
* // (6)
(cos2SM + (B / 4.0)
* (cosSigma * (-1.0 + 2.0 * cos2SMSq) - (B / 6.0) * cos2SM
* (-3.0 + 4.0 * sinSigma * sinSigma)
* (-3.0 + 4.0 * cos2SMSq)));
lambda = L
+ (1.0 - C)
* f
* sinAlpha
* (sigma + C * sinSigma
* (cos2SM + C * cosSigma * (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)
double delta = (lambda - lambdaOrig) / lambda;
if (Math.abs(delta) < 1.0e-12) {
break;
}
}
double distance = (b * A * (sigma - deltaSigma));
results[0] = distance;
if (results.length > 1) {
double initialBearing = Math.atan2(cosU2 * sinLambda, cosU1 * sinU2
- sinU1 * cosU2 * cosLambda);
initialBearing *= 180.0 / Math.PI;
results[1] = initialBearing;
if (results.length > 2) {
double finalBearing = Math.atan2(cosU1 * sinLambda, -sinU1 * cosU2
+ cosU1 * sinU2 * cosLambda);
finalBearing *= 180.0 / Math.PI;
results[2] = finalBearing;
}
}
}
/*
* Vincenty Direct Solution of Geodesics on the Ellipsoid (c) Chris Veness
* 2005-2012
*
* from: Vincenty direct formula - T Vincenty, "Direct and Inverse Solutions
* of Geodesics on the Ellipsoid with application of nested equations", Survey
* Review, vol XXII no 176, 1975 http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
*/
/**
* Calculates destination point and final bearing given given start point,
* bearing & distance, using Vincenty inverse formula for ellipsoids
*
* @param lat1
* start point latitude
* @param lon1
* start point longitude
* @param brng
* initial bearing in decimal degrees
* @param dist
* distance along bearing in metres
* @returns an array of the desination point coordinates and the final bearing
*/
public static void computeDestinationAndBearing(double lat1, double lon1,
double brng, double dist, double results[]) {
double a = 6378137, b = 6356752.3142, f = 1 / 298.257223563; // WGS-84
// ellipsiod
double s = dist;
double alpha1 = toRad(brng);
double sinAlpha1 = Math.sin(alpha1);
double cosAlpha1 = Math.cos(alpha1);
double tanU1 = (1 - f) * Math.tan(toRad(lat1));
double cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1)), sinU1 = tanU1 * cosU1;
double sigma1 = Math.atan2(tanU1, cosAlpha1);
double sinAlpha = cosU1 * sinAlpha1;
double cosSqAlpha = 1 - sinAlpha * sinAlpha;
double uSq = cosSqAlpha * (a * a - b * b) / (b * b);
double A = 1 + uSq / 16384
* (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
double B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
double sinSigma = 0, cosSigma = 0, deltaSigma = 0, cos2SigmaM = 0;
double sigma = s / (b * A), sigmaP = 2 * Math.PI;
while (Math.abs(sigma - sigmaP) > 1e-12) {
cos2SigmaM = Math.cos(2 * sigma1 + sigma);
sinSigma = Math.sin(sigma);
cosSigma = Math.cos(sigma);
deltaSigma = B
* sinSigma
* (cos2SigmaM + B
/ 4
* (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B / 6
* cos2SigmaM * (-3 + 4 * sinSigma * sinSigma)
* (-3 + 4 * cos2SigmaM * cos2SigmaM)));
sigmaP = sigma;
sigma = s / (b * A) + deltaSigma;
}
double tmp = sinU1 * sinSigma - cosU1 * cosSigma * cosAlpha1;
double lat2 = Math.atan2(sinU1 * cosSigma + cosU1 * sinSigma * cosAlpha1,
(1 - f) * Math.sqrt(sinAlpha * sinAlpha + tmp * tmp));
double lambda = Math.atan2(sinSigma * sinAlpha1, cosU1 * cosSigma - sinU1
* sinSigma * cosAlpha1);
double C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
double L = lambda
- (1 - C)
* f
* sinAlpha
* (sigma + C * sinSigma
* (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));
double lon2 = (toRad(lon1) + L + 3 * Math.PI) % (2 * Math.PI) - Math.PI; // normalise
// to
// -180...+180
double revAz = Math.atan2(sinAlpha, -tmp); // final bearing, if required
results[0] = toDegrees(lat2);
results[1] = toDegrees(lon2);
results[2] = toDegrees(revAz);
}
private static double toRad(double angle) {
return angle * Math.PI / 180;
}
private static double toDegrees(double radians) {
return radians * 180 / Math.PI;
}
}
public-class-LatLngUtils{
/**
*@param-lat1
*初始纬度
*@param lon1
*初始经度
*@param-lat2
*目的地纬度
*@param lon2
*目的经度
*@param结果
*填入距离、初始方位和最终方位
*方位
*/
公共静态无效计算距离和轴承（双lat1，双lon1，
双lat2，双lon2，双结果[]）{
//基于http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
//使用“逆公式”（第4节）
int最大值=20；
//将横向/纵向转换为弧度
lat1*=Math.PI/180.0；
lat2*=数学PI/180.0；
lon1*=数学PI/180.0；
lon2*=数学PI/180.0；
双a=6378137.0；//WGS84长轴
双b=6356752.3142；//WGS84半长轴
双f=（a-b）/a；
双asqminusbsqovervsq=（a*a-b*b）/（b*b）；
双L=lon2-lon1；
双A=0.0；
double U1=数学atan（（1.0-f）*数学tan（lat1））；
double U2=数学atan（（1.0-f）*数学tan（lat2））；
双cosU1=数学cos（U1）；
双cosU2=数学cos（U2）；
double sinU1=数学sin（U1）；
double sinU2=数学sin（U2）；
双cosu1cos2=cosU1*cosU2；
双sinU1sinU2=sinU1*sinU2；
双西格玛=0.0；
双deltaSigma=0.0；
双cosSqAlpha=0.0；
双cos2SM=0.0；
双余弦σ=0.0；
双sinSigma=0.0；
双余弦λ=0.0；
双sinLambda=0.0；
双λ=L；//初始猜测
对于（int-iter=0；iter1）{
双初始轴承=数学atan2（cosU2*sinLambda，cosU1*sinU2
-sinU1*cosU2*cosLambda）；
初始轴承*=180.0/Math.PI；
结果[1]=初始轴承；
如果（结果长度>2）{
双最终轴承=数学atan2（cosU1*sinLambda，-sinU1*cosU2
+cosU1*sinU2*cosLambda）；
最终轴承*=180.0/Math.PI；
结果[2]=最终结果；
}
}
}
/*
*椭球体上测地线的Vincenty直接解（c）
* 2005-2012
*
*摘自：Vincenty直接公式-T Vincenty，“正解和逆解
*应用嵌套方程在椭球体上进行测地线测量”，测量
*审查，第二十二卷第176期，1975年http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
*/
/**
*计算给定起点的终点和最终方位，
*方位和距离，使用椭球体的Vincenty逆公式
*
*@param-lat1
*起点纬度
*@param lon1
*起点经度
*@param brng
*初始方位角（十进制度数）
*@param d
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Google Maps Geometry</title>
<script src="http://maps.google.com/maps/api/js?sensor=false"
type="text/javascript"></script>
</head>
<body>
<div id="map" style="width: 400px; height: 300px"></div>
<script type="text/javascript">
Number.prototype.toRad = function() {
return this * Math.PI / 180;
}
Number.prototype.toDeg = function() {
return this * 180 / Math.PI;
}
google.maps.LatLng.prototype.destinationPoint = function(brng, dist) {
dist = dist / 6371;
brng = brng.toRad();
var lat1 = this.lat().toRad(), lon1 = this.lng().toRad();
var lat2 = Math.asin(Math.sin(lat1) * Math.cos(dist) +
Math.cos(lat1) * Math.sin(dist) * Math.cos(brng));
var lon2 = lon1 + Math.atan2(Math.sin(brng) * Math.sin(dist) *
Math.cos(lat1),
Math.cos(dist) - Math.sin(lat1) *
Math.sin(lat2));
if (isNaN(lat2) || isNaN(lon2)) return null;
return new google.maps.LatLng(lat2.toDeg(), lon2.toDeg());
}
var pointA = new google.maps.LatLng(40.70, -74.00); // Circle center
var radius = 10; // 10km
var mapOpt = {
mapTypeId: google.maps.MapTypeId.TERRAIN,
center: pointA,
zoom: 10
};
var map = new google.maps.Map(document.getElementById("map"), mapOpt);
// Draw the circle
new google.maps.Circle({
center: pointA,
radius: radius * 1000, // Convert to meters
fillColor: '#FF0000',
fillOpacity: 0.2,
map: map
});
// Show marker at circle center
new google.maps.Marker({
position: pointA,
map: map
});
// Show marker at destination point
new google.maps.Marker({
position: pointA.destinationPoint(90, radius),
map: map
});
</script>
</body>
</html>
var pointA = new google.maps.LatLng(85, 0); // Close to north pole
var radius = 1000; // 1000km
public class LatLngUtils {
/**
* @param lat1
* Initial latitude
* @param lon1
* Initial longitude
* @param lat2
* destination latitude
* @param lon2
* destination longitude
* @param results
* To be populated with the distance, initial bearing and final
* bearing
*/
public static void computeDistanceAndBearing(double lat1, double lon1,
double lat2, double lon2, double results[]) {
// Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
// using the "Inverse Formula" (section 4)
int MAXITERS = 20;
// Convert lat/long to radians
lat1 *= Math.PI / 180.0;
lat2 *= Math.PI / 180.0;
lon1 *= Math.PI / 180.0;
lon2 *= Math.PI / 180.0;
double a = 6378137.0; // WGS84 major axis
double b = 6356752.3142; // WGS84 semi-major axis
double f = (a - b) / a;
double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);
double L = lon2 - lon1;
double A = 0.0;
double U1 = Math.atan((1.0 - f) * Math.tan(lat1));
double U2 = Math.atan((1.0 - f) * Math.tan(lat2));
double cosU1 = Math.cos(U1);
double cosU2 = Math.cos(U2);
double sinU1 = Math.sin(U1);
double sinU2 = Math.sin(U2);
double cosU1cosU2 = cosU1 * cosU2;
double sinU1sinU2 = sinU1 * sinU2;
double sigma = 0.0;
double deltaSigma = 0.0;
double cosSqAlpha = 0.0;
double cos2SM = 0.0;
double cosSigma = 0.0;
double sinSigma = 0.0;
double cosLambda = 0.0;
double sinLambda = 0.0;
double lambda = L; // initial guess
for (int iter = 0; iter < MAXITERS; iter++) {
double lambdaOrig = lambda;
cosLambda = Math.cos(lambda);
sinLambda = Math.sin(lambda);
double t1 = cosU2 * sinLambda;
double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
double sinSqSigma = t1 * t1 + t2 * t2; // (14)
sinSigma = Math.sqrt(sinSqSigma);
cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
sigma = Math.atan2(sinSigma, cosSigma); // (16)
double sinAlpha = (sinSigma == 0) ? 0.0 : cosU1cosU2 * sinLambda
/ sinSigma; // (17)
cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
cos2SM = (cosSqAlpha == 0) ? 0.0 : cosSigma - 2.0 * sinU1sinU2
/ cosSqAlpha; // (18)
double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
A = 1 + (uSquared / 16384.0) * // (3)
(4096.0 + uSquared * (-768 + uSquared * (320.0 - 175.0 * uSquared)));
double B = (uSquared / 1024.0) * // (4)
(256.0 + uSquared * (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
double C = (f / 16.0) * cosSqAlpha * (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
double cos2SMSq = cos2SM * cos2SM;
deltaSigma = B
* sinSigma
* // (6)
(cos2SM + (B / 4.0)
* (cosSigma * (-1.0 + 2.0 * cos2SMSq) - (B / 6.0) * cos2SM
* (-3.0 + 4.0 * sinSigma * sinSigma)
* (-3.0 + 4.0 * cos2SMSq)));
lambda = L
+ (1.0 - C)
* f
* sinAlpha
* (sigma + C * sinSigma
* (cos2SM + C * cosSigma * (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)
double delta = (lambda - lambdaOrig) / lambda;
if (Math.abs(delta) < 1.0e-12) {
break;
}
}
double distance = (b * A * (sigma - deltaSigma));
results[0] = distance;
if (results.length > 1) {
double initialBearing = Math.atan2(cosU2 * sinLambda, cosU1 * sinU2
- sinU1 * cosU2 * cosLambda);
initialBearing *= 180.0 / Math.PI;
results[1] = initialBearing;
if (results.length > 2) {
double finalBearing = Math.atan2(cosU1 * sinLambda, -sinU1 * cosU2
+ cosU1 * sinU2 * cosLambda);
finalBearing *= 180.0 / Math.PI;
results[2] = finalBearing;
}
}
}
/*
* Vincenty Direct Solution of Geodesics on the Ellipsoid (c) Chris Veness
* 2005-2012
*
* from: Vincenty direct formula - T Vincenty, "Direct and Inverse Solutions
* of Geodesics on the Ellipsoid with application of nested equations", Survey
* Review, vol XXII no 176, 1975 http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
*/
/**
* Calculates destination point and final bearing given given start point,
* bearing & distance, using Vincenty inverse formula for ellipsoids
*
* @param lat1
* start point latitude
* @param lon1
* start point longitude
* @param brng
* initial bearing in decimal degrees
* @param dist
* distance along bearing in metres
* @returns an array of the desination point coordinates and the final bearing
*/
public static void computeDestinationAndBearing(double lat1, double lon1,
double brng, double dist, double results[]) {
double a = 6378137, b = 6356752.3142, f = 1 / 298.257223563; // WGS-84
// ellipsiod
double s = dist;
double alpha1 = toRad(brng);
double sinAlpha1 = Math.sin(alpha1);
double cosAlpha1 = Math.cos(alpha1);
double tanU1 = (1 - f) * Math.tan(toRad(lat1));
double cosU1 = 1 / Math.sqrt((1 + tanU1 * tanU1)), sinU1 = tanU1 * cosU1;
double sigma1 = Math.atan2(tanU1, cosAlpha1);
double sinAlpha = cosU1 * sinAlpha1;
double cosSqAlpha = 1 - sinAlpha * sinAlpha;
double uSq = cosSqAlpha * (a * a - b * b) / (b * b);
double A = 1 + uSq / 16384
* (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
double B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
double sinSigma = 0, cosSigma = 0, deltaSigma = 0, cos2SigmaM = 0;
double sigma = s / (b * A), sigmaP = 2 * Math.PI;
while (Math.abs(sigma - sigmaP) > 1e-12) {
cos2SigmaM = Math.cos(2 * sigma1 + sigma);
sinSigma = Math.sin(sigma);
cosSigma = Math.cos(sigma);
deltaSigma = B
* sinSigma
* (cos2SigmaM + B
/ 4
* (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B / 6
* cos2SigmaM * (-3 + 4 * sinSigma * sinSigma)
* (-3 + 4 * cos2SigmaM * cos2SigmaM)));
sigmaP = sigma;
sigma = s / (b * A) + deltaSigma;
}
double tmp = sinU1 * sinSigma - cosU1 * cosSigma * cosAlpha1;
double lat2 = Math.atan2(sinU1 * cosSigma + cosU1 * sinSigma * cosAlpha1,
(1 - f) * Math.sqrt(sinAlpha * sinAlpha + tmp * tmp));
double lambda = Math.atan2(sinSigma * sinAlpha1, cosU1 * cosSigma - sinU1
* sinSigma * cosAlpha1);
double C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
double L = lambda
- (1 - C)
* f
* sinAlpha
* (sigma + C * sinSigma
* (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));
double lon2 = (toRad(lon1) + L + 3 * Math.PI) % (2 * Math.PI) - Math.PI; // normalise
// to
// -180...+180
double revAz = Math.atan2(sinAlpha, -tmp); // final bearing, if required
results[0] = toDegrees(lat2);
results[1] = toDegrees(lon2);
results[2] = toDegrees(revAz);
}
private static double toRad(double angle) {
return angle * Math.PI / 180;
}
private static double toDegrees(double radians) {
return radians * 180 / Math.PI;
}
}
var pointA = new google.maps.LatLng(25.48, -71.26);
var distance = 10; // 10 metres
var bearing = 90; // 90 degrees
var pointB = google.maps.geometry.spherical.computeOffset(pointA, distance, bearing);
private LatLng getDestinationPoint (LatLng pointStart, double bearing, double distance) {
distance = distance / 6371000;
bearing = getRad(bearing);
double lat1 = getRad(pointStart.latitude);
double lon1 = getRad(pointStart.longitude);
double lat2 = Math.asin(Math.sin(lat1) * Math.cos(distance) +
Math.cos(lat1) * Math.sin(distance) * Math.cos(bearing));
double lon2 = lon1 + Math.atan2(Math.sin(bearing) * Math.sin(distance) *
Math.cos(lat1),
Math.cos(distance) - Math.sin(lat1) *
Math.sin(lat2));
if (Double.isNaN(lat2) || Double.isNaN(lon2)) return null;
return new LatLng(getDeg(lat2), getDeg(lon2));
}
private double getRad(double degrees) {
return degrees * Math.PI / 180;
}
private double getDeg(double rad) {
return rad * 180 / Math.PI;
}