I tried using this:
function getRandomInRange(from, to, fixed) {
return parseFloat((Math.random() * (to - from) + from).toFixed(fixed));
}
var latLongPairs = 4;
for(var i =0; i<latLongPairs; i++) {
console.log(`${getRandomInRange(-180, 180, 3)}, ${getRandomInRange(-180, 180, 3)}`);
}
That's ok for random numbers like 39.21988,9.124741 but they might end up not valid coordinates. And I need 100 of them.
Your latitude range is incorrect - it should be ±90.
function getRandomInRange(from, to) {
return Math.random() * (to - from) + from;
}
const latLongPairs = 4;
for (let i = 0; i < latLongPairs; ++i) {
let lat = getRandomInRange(-90, 90);
let lon = getRandomInRange(-180, 180);
console.log(`${lat.toFixed(3)}, ${lon.toFixed(3)}`);
}
You might need to provide some initial Latitude and longitude with some radius (in meters)
var getRandomLocation = function(latitude, longitude, radiusInMeters) {
var getRandomCoordinates = function(radius, uniform) {
// Generate two random numbers
var a = Math.random(),
b = Math.random();
// Flip for more uniformity.
if (uniform) {
if (b < a) {
var c = b;
b = a;
a = c;
}
}
// It's all triangles.
return [
b * radius * Math.cos(2 * Math.PI * a / b),
b * radius * Math.sin(2 * Math.PI * a / b)
];
};
var randomCoordinates = getRandomCoordinates(radiusInMeters, true);
// Earths radius in meters via WGS 84 model.
var earth = 6378137;
// Offsets in meters.
var northOffset = randomCoordinates[0],
eastOffset = randomCoordinates[1];
// Offset coordinates in radians.
var offsetLatitude = northOffset / earth,
offsetLongitude = eastOffset / (earth * Math.cos(Math.PI * (latitude / 180)));
return `${latitude + (offsetLatitude * (180 / Math.PI))}, ${longitude + (offsetLongitude * (180 / Math.PI))}`
};
for (i = 0; i < 182; i++) {
console.log(getRandomLocation(41.8819, -87.6278, 50))
}
I have this code to test if my customer near or far from my center (at least 2 km)...
my problem is .. in some mobiles it's take some secondes to get real customer GPS loaction (depend on his device quality) that's why i want to try more than one time and i want to wait some second berfor give him error message ... lets say i want to try 5 time in 30 seconds to get his real loaction after that i want to give him error message
<script type="text/javascript">
$(document).ready(function () {
var Options = { enableHighAccuracy: true, maximumAge: 0, timeout: 60000 };
navigator.geolocation.watchPosition(Success, Error, Options);
function Success(position) {
if (haversineDistance([position.coords.longitude, position.coords.latitude], [45.896328,28.3350241], false) < 2) {
alert('ok you are here');
}
else {
alert('sorry you are not here');
}
}
function Error() {
alert('error');
}
function haversineDistance(coords1, coords2, isMiles) {
function toRad(x) {
return x * Math.PI / 180;
}
var lon1 = coords1[0];
var lat1 = coords1[1];
var lon2 = coords2[0];
var lat2 = coords2[1];
var R = 6371; // km
var x1 = lat2 - lat1;
var dLat = toRad(x1);
var x2 = lon2 - lon1;
var dLon = toRad(x2)
var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
Math.cos(toRad(lat1)) * Math.cos(toRad(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;
if (isMiles) d /= 1.60934;
return d;
}
});
So I have the following piece of javascript, and I have no idea why I keep getting Nan whenever I try to console log stuff inside the distance function. Even if I just log lat1, I'm getting NaN. But this only happens inside the getDistance function, anywhere else all is working fine. Obviously the rest of the function isn't working as well since everything returns NaN.
(function(){
var lat = 52.387388 ; //example lat
var lon = 4.646219 ; //example lon
function initCoords() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(createLatLong);
} else {
showError("Your browser does not support Geolocation!");
}
}
function createLatLong(position) {
var lat2 = position.coords.latitude;
var long2 = position.coords.longitude;
console.log(lat + "createLatLong");
getDistance();
}
function getDistance(lat, lon, lat2, long2) {
var R = 6371;
var dLat = (lat2-lat) * Math.PI / 180;
var dLon = (long2-lon) * Math.PI / 180;
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(lat * Math.PI / 180 ) * Math.cos(lat2 * Math.PI / 180 ) *
Math.sin(dLon/2) * Math.sin(dLon/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
return d; }
window.onload = initCoords;
})();
Here's a fiddle
You're declaring the "getDistance()" function with parameters that hide the variables declared outside the function. Either pass the parameters in when you call it:
getDistance(lat, lon, lat2, long2);
or else get rid of the formal parameters in the function declaration.
Due to rounding of float number, 1-a might be a negative value.
Please replace line:
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
to:
var tan2 = 1-a;
if (tan2 < 0) {
tan2 = 0;
}
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(tan2));
i have a polyine which i have drawn with latlngs obtained from google maps directions service.
Now i want to find a point on the polyline that is closest to a given point.
The obvious way (to me) is to kind of loop through all the points in the polyline and find the distance between them and the given point, however this is inefficient because the points on the polyline can potentially be large.
I would be glad to hear any alternatives of doing this.
Thanks in advance.
I needed a cleaner version that was ported to V3, so here it is:
/**
* Snap marker to closest point on a line.
*
* Based on Distance to line example by
* Marcelo, maps.forum.nu - http://maps.forum.nu/gm_mouse_dist_to_line.html
* Then
* # work of Björn Brala - Swis BV who wrapped the algorithm in a class operating on GMap Objects
* And now
* Bill Chadwick, who factored the basic algorithm out of the class (removing much intermediate storage of results)
* and added distance along line to nearest point calculation
* Followed by
* Robert Crowe, who ported it to v3 of the Google Maps API and factored out the marker to make it more general.
*
* Usage:
*
* Create the class
* var oSnap = new cSnapToRoute();
*
* Initialize the subjects
* oSnap.init(oMap, oPolyline);
*
**/
function cSnapToRoute() {
this.routePoints = Array();
this.routePixels = Array();
this._oMap;
this._oPolyline;
/**
* #desc Initialize the objects.
* #param Map object
* #param GPolyline object - the 'route'
**/
this.init = function (oMap, oPolyline) {
this._oMap = oMap;
this._oPolyline = oPolyline;
this.loadRouteData(); // Load needed data for point calculations
}
/**
* #desc internal use only, Load route points into RoutePixel array for calculations, do this whenever zoom changes
**/
this.loadRouteData = function () {
this.routePixels = new Array();
var proj = this._oMap.getProjection();
for (var i = 0; i < this._oPolyline.getPath().getLength(); i++) {
var Px = proj.fromLatLngToPoint(this._oPolyline.getPath().getAt(i));
this.routePixels.push(Px);
}
}
/**
* #desc Get closest point on route to test point
* #param GLatLng() the test point
* #return new GLatLng();
**/
this.getClosestLatLng = function (latlng) {
var r = this.distanceToLines(latlng);
var proj = this._oMap.getProjection();
return proj.fromPointToLatLng(new google.maps.Point(r.x, r.y));
}
/**
* #desc Get distance along route in meters of closest point on route to test point
* #param GLatLng() the test point
* #return distance in meters;
**/
this.getDistAlongRoute = function (latlng) {
var r = this.distanceToLines(latlng);
return this.getDistToLine(r.i, r.fTo);
}
/**
* #desc internal use only, gets test point xy and then calls fundamental algorithm
**/
this.distanceToLines = function (thisLatLng) {
var tm = this._oMap;
var proj = this._oMap.getProjection();
var thisPx = proj.fromLatLngToPoint(thisLatLng);
var routePixels = this.routePixels;
return getClosestPointOnLines(thisPx, routePixels);
}
/**
* #desc internal use only, find distance along route to point nearest test point
**/
this.getDistToLine = function (iLine, fTo) {
var routeOverlay = this._oPolyline;
var d = 0;
for (var n = 1 ; n < iLine ; n++) {
d += routeOverlay.getPath().getAt(n - 1).distanceFrom(routeOverlay.getPath().getAt(n));
}
d += routeOverlay.getPath().getAt(iLine - 1).distanceFrom(routeOverlay.getPath().getAt(iLine)) * fTo;
return d;
}
}
/* desc Static function. Find point on lines nearest test point
test point pXy with properties .x and .y
lines defined by array aXys with nodes having properties .x and .y
return is object with .x and .y properties and property i indicating nearest segment in aXys
and property fFrom the fractional distance of the returned point from aXy[i-1]
and property fTo the fractional distance of the returned point from aXy[i] */
function getClosestPointOnLines(pXy, aXys) {
var minDist;
var fTo;
var fFrom;
var x;
var y;
var i;
var dist;
if (aXys.length > 1) {
for (var n = 1 ; n < aXys.length ; n++) {
if (aXys[n].x != aXys[n - 1].x) {
var a = (aXys[n].y - aXys[n - 1].y) / (aXys[n].x - aXys[n - 1].x);
var b = aXys[n].y - a * aXys[n].x;
dist = Math.abs(a * pXy.x + b - pXy.y) / Math.sqrt(a * a + 1);
}
else
dist = Math.abs(pXy.x - aXys[n].x)
// length^2 of line segment
var rl2 = Math.pow(aXys[n].y - aXys[n - 1].y, 2) + Math.pow(aXys[n].x - aXys[n - 1].x, 2);
// distance^2 of pt to end line segment
var ln2 = Math.pow(aXys[n].y - pXy.y, 2) + Math.pow(aXys[n].x - pXy.x, 2);
// distance^2 of pt to begin line segment
var lnm12 = Math.pow(aXys[n - 1].y - pXy.y, 2) + Math.pow(aXys[n - 1].x - pXy.x, 2);
// minimum distance^2 of pt to infinite line
var dist2 = Math.pow(dist, 2);
// calculated length^2 of line segment
var calcrl2 = ln2 - dist2 + lnm12 - dist2;
// redefine minimum distance to line segment (not infinite line) if necessary
if (calcrl2 > rl2)
dist = Math.sqrt(Math.min(ln2, lnm12));
if ((minDist == null) || (minDist > dist)) {
if (calcrl2 > rl2) {
if (lnm12 < ln2) {
fTo = 0;//nearer to previous point
fFrom = 1;
}
else {
fFrom = 0;//nearer to current point
fTo = 1;
}
}
else {
// perpendicular from point intersects line segment
fTo = ((Math.sqrt(lnm12 - dist2)) / Math.sqrt(rl2));
fFrom = ((Math.sqrt(ln2 - dist2)) / Math.sqrt(rl2));
}
minDist = dist;
i = n;
}
}
var dx = aXys[i - 1].x - aXys[i].x;
var dy = aXys[i - 1].y - aXys[i].y;
x = aXys[i - 1].x - (dx * fTo);
y = aXys[i - 1].y - (dy * fTo);
}
return { 'x': x, 'y': y, 'i': i, 'fTo': fTo, 'fFrom': fFrom };
}
See Bill Chadwick's example here:
http://www.bdcc.co.uk/Gmaps/BdccGmapBits.htm
above example ported to v3 (code at bottom of this answer)
on his page under:
DISTANCE POINT TO POLYLINE OR POLYGON
from that post:
There is a similar, better demo here http://wtp2.appspot.com/cSnapToRouteDemo.html
It is finding the closest point on the line to the mouse. Also note that it is a Google Maps API v2 example (but the principle with v3 would be the same).
// Code to find the distance in metres between a lat/lng point and a polyline of lat/lng points
// All in WGS84. Free for any use.
//
// Bill Chadwick 2007
// updated to Google Maps API v3, Lawrence Ross 2014
// Construct a bdccGeo from its latitude and longitude in degrees
function bdccGeo(lat, lon)
{
var theta = (lon * Math.PI / 180.0);
var rlat = bdccGeoGeocentricLatitude(lat * Math.PI / 180.0);
var c = Math.cos(rlat);
this.x = c * Math.cos(theta);
this.y = c * Math.sin(theta);
this.z = Math.sin(rlat);
}
bdccGeo.prototype = new bdccGeo();
// internal helper functions =========================================
// Convert from geographic to geocentric latitude (radians).
function bdccGeoGeocentricLatitude(geographicLatitude)
{
var flattening = 1.0 / 298.257223563;//WGS84
var f = (1.0 - flattening) * (1.0 - flattening);
return Math.atan((Math.tan(geographicLatitude) * f));
}
// Returns the two antipodal points of intersection of two great
// circles defined by the arcs geo1 to geo2 and
// geo3 to geo4. Returns a point as a Geo, use .antipode to get the other point
function bdccGeoGetIntersection( geo1, geo2, geo3, geo4)
{
var geoCross1 = geo1.crossNormalize(geo2);
var geoCross2 = geo3.crossNormalize(geo4);
return geoCross1.crossNormalize(geoCross2);
}
//from Radians to Meters
function bdccGeoRadiansToMeters(rad)
{
return rad * 6378137.0; // WGS84 Equatorial Radius in Meters
}
//from Meters to Radians
function bdccGeoMetersToRadians(m)
{
return m / 6378137.0; // WGS84 Equatorial Radius in Meters
}
// properties =================================================
bdccGeo.prototype.getLatitudeRadians = function()
{
return (bdccGeoGeographicLatitude(Math.atan2(this.z,
Math.sqrt((this.x * this.x) + (this.y * this.y)))));
}
bdccGeo.prototype.getLongitudeRadians = function()
{
return (Math.atan2(this.y, this.x));
}
bdccGeo.prototype.getLatitude = function()
{
return this.getLatitudeRadians() * 180.0 / Math.PI;
}
bdccGeo.prototype.getLongitude = function()
{
return this.getLongitudeRadians() * 180.0 / Math.PI ;
}
// Methods =================================================
//Maths
bdccGeo.prototype.dot = function( b)
{
return ((this.x * b.x) + (this.y * b.y) + (this.z * b.z));
}
//More Maths
bdccGeo.prototype.crossLength = function( b)
{
var x = (this.y * b.z) - (this.z * b.y);
var y = (this.z * b.x) - (this.x * b.z);
var z = (this.x * b.y) - (this.y * b.x);
return Math.sqrt((x * x) + (y * y) + (z * z));
}
//More Maths
bdccGeo.prototype.scale = function( s)
{
var r = new bdccGeo(0,0);
r.x = this.x * s;
r.y = this.y * s;
r.z = this.z * s;
return r;
}
// More Maths
bdccGeo.prototype.crossNormalize = function( b)
{
var x = (this.y * b.z) - (this.z * b.y);
var y = (this.z * b.x) - (this.x * b.z);
var z = (this.x * b.y) - (this.y * b.x);
var L = Math.sqrt((x * x) + (y * y) + (z * z));
var r = new bdccGeo(0,0);
r.x = x / L;
r.y = y / L;
r.z = z / L;
return r;
}
// point on opposite side of the world to this point
bdccGeo.prototype.antipode = function()
{
return this.scale(-1.0);
}
//distance in radians from this point to point v2
bdccGeo.prototype.distance = function( v2)
{
return Math.atan2(v2.crossLength(this), v2.dot(this));
}
//returns in meters the minimum of the perpendicular distance of this point from the line segment geo1-geo2
//and the distance from this point to the line segment ends in geo1 and geo2
bdccGeo.prototype.distanceToLineSegMtrs = function(geo1, geo2)
{
//point on unit sphere above origin and normal to plane of geo1,geo2
//could be either side of the plane
var p2 = geo1.crossNormalize(geo2);
// intersection of GC normal to geo1/geo2 passing through p with GC geo1/geo2
var ip = bdccGeoGetIntersection(geo1,geo2,this,p2);
//need to check that ip or its antipode is between p1 and p2
var d = geo1.distance(geo2);
var d1p = geo1.distance(ip);
var d2p = geo2.distance(ip);
//window.status = d + ", " + d1p + ", " + d2p;
if ((d >= d1p) && (d >= d2p))
return bdccGeoRadiansToMeters(this.distance(ip));
else
{
ip = ip.antipode();
d1p = geo1.distance(ip);
d2p = geo2.distance(ip);
}
if ((d >= d1p) && (d >= d2p))
return bdccGeoRadiansToMeters(this.distance(ip));
else
return bdccGeoRadiansToMeters(Math.min(geo1.distance(this),geo2.distance(this)));
}
// distance in meters from GLatLng point to GPolyline or GPolygon poly
function bdccGeoDistanceToPolyMtrs(poly, point)
{
var d = 999999999;
var i;
var p = new bdccGeo(point.lat(),point.lng());
for(i=0; i<(poly.getPath().getLength()-1); i++)
{
var p1 = poly.getPath().getAt(i);
var l1 = new bdccGeo(p1.lat(),p1.lng());
var p2 = poly.getPath().getAt(i+1);
var l2 = new bdccGeo(p2.lat(),p2.lng());
var dp = p.distanceToLineSegMtrs(l1,l2);
if(dp < d)
d = dp;
}
return d;
}
// get a new GLatLng distanceMeters away on the compass bearing azimuthDegrees
// from the GLatLng point - accurate to better than 200m in 140km (20m in 14km) in the UK
function bdccGeoPointAtRangeAndBearing (point, distanceMeters, azimuthDegrees)
{
var latr = point.lat() * Math.PI / 180.0;
var lonr = point.lng() * Math.PI / 180.0;
var coslat = Math.cos(latr);
var sinlat = Math.sin(latr);
var az = azimuthDegrees* Math.PI / 180.0;
var cosaz = Math.cos(az);
var sinaz = Math.sin(az);
var dr = distanceMeters / 6378137.0; // distance in radians using WGS84 Equatorial Radius
var sind = Math.sin(dr);
var cosd = Math.cos(dr);
return new google.maps.LatLng(Math.asin((sinlat * cosd) + (coslat * sind * cosaz)) * 180.0 / Math.PI,
(Math.atan2((sind * sinaz), (coslat * cosd) - (sinlat * sind * cosaz)) + lonr) * 180.0 / Math.PI);
}
I do not think you can avoid checking all the points.
What if the not checked point is the nearest one?
If you have to do this operation many times, you can choose a data structure that is optimized for such a search, quadtree for example.
Note that you should not use lat lng as Descartes coordinates.
See also Finding nearest point in an efficient way
That is for the 2D plane, and not for lat lng, but you can approximate: https://stackoverflow.com/a/16271669/59019
Inspired by jmihalicza's answer, i came up with this function to find the closest point in an array of LatLngs to a given LatLng.
function closest takes a LatLng(llng) and an array of LatLngs (listData) and finds the distance between each latlng in the array and the given latlng, it then finds the least distance and returns the Latlng from the list which provided that distance.
function closest(llng, listData) {
var arr = listData;
var pnt = llng;
var distArr = [];
var dist = google.maps.geometry.spherical.computeDistanceBetween;
for (index in arr)
distArr.push([arr[index], dist(pnt, arr[index])]);
return distArr.sort(function(a,b){
return a[1]-b[1];
})[0][0];
}
EDIT
If you don't have access to the array of LatLngs which make up the polyline, but have access to the polyline itself, you can use polyline's getPath method to get the path which is an MVC array so you can use .getArray() to return an array of LatLngs to use with the above function (closest).
I've been searching for a solution for this and haven't been successful, what I want to do is that by specifying a radius and a center, to draw a circle on a map. The documentation for Bing Maps Ajax Control 6.3 for shapes doesn't cover circles. Is there a way to draw circles on a map?
Any help would be appreciated.
You should check Mike Garza's blog (Garzilla) that created really interesting examples around your needs: http://www.garzilla.net/vemaps/CircleDragHandle.aspx
Here is a sample code to generate the circle locations:
function buildCircle(latin, lonin, radius) {
var locs = new Array();
var lat1 = latin * Math.PI / 180.0;
var lon1 = lonin * Math.PI / 180.0;
var d = radius / 3956;
var x;
for (x = 0; x <= 360; x+=10) {
var tc = (x / 90) * Math.PI / 2;
var lat = Math.asin(Math.sin(lat1) * Math.cos(d) + Math.cos(lat1) * Math.sin(d) * Math.cos(tc));
lat = 180.0 * lat / Math.PI;
var lon;
if (Math.cos(lat1) == 0) {
lon = lonin; // endpoint a pole
}
else {
lon = ((lon1 - Math.asin(Math.sin(tc) * Math.sin(d) / Math.cos(lat1)) + Math.PI) % (2 * Math.PI)) - Math.PI;
}
lon = 180.0 * lon / Math.PI;
var loc = new VELatLong(lat, lon);
locs.push(loc);
}
return locs;
}
And here the code to add it on the map and use the previous method:
//Build circle
circle = new VEShape(VEShapeType.Polygon, circlePoints);
circle.HideIcon();
circle.SetLineWidth(2);
map.AddShape(circle);