i am creating flutter attendance app where i want to check when user is marking attendance he/she is available in office area or not? if not show them how much distance they are away from radius.
i tried using this but not getting the appropriate result. i want to check 200m radius from lat long.
double geDistance(double lat1, double lon1, double lat2, double lon2) {
double theta = lon1 - lon2;
double dist = sin(toRadians(lat1)) * sin(toRadians(lat2)) +
cos(toRadians(lat1)) * cos(toRadians(lat2)) * cos(toRadians(theta));
dist = acos(dist);
dist = toDegrees(dist);
dist = dist * 60 * 1.1515;
dist = dist * 1000 * 1.609344;
///dist in meter
return dist;
}
double toRadians(double degree) {
return degree * pi / 180;
}
double toDegrees(double radian) {
return radian * 180 / pi;
}
i know geofense can resolve accurately this but i have no idea which method can help me to check user location is inside radius or not.
Related
I have a coordinate. How can we calculate the bounds that the point is centered in map?
Call that point O and its bound has size 5x5m
.
Do any of you have a solution? I don't have a solution yet.
Solution:
* Returns the Point resulting from moving a distance from an origin in the
* specified heading (expressed in degrees clockwise from north).
*
* #param from The Point from which to start.
* #param distance The distance to travel.
* #param heading The heading in degrees clockwise from north.
*/
public static Point computeOffset(Point from, double distance, double heading)
{
distance /= MathUtil.EARTH_RADIUS;
heading = MathUtil.convertToRadians(heading);
// http://williams.best.vwh.net/avform.htm#LL
double fromLat = MathUtil.convertToRadians(from.Lat);
double fromLng = MathUtil.convertToRadians(from.Lng);
double cosDistance = Math.Cos(distance);
double sinDistance = Math.Sin(distance);
double sinFromLat = Math.Sin(fromLat);
double cosFromLat = Math.Cos(fromLat);
double sinLat = cosDistance * sinFromLat + sinDistance * cosFromLat * Math.Cos(heading);
double dLng = Math.Atan2(sinDistance * cosFromLat * Math.Sin(heading), cosDistance - sinFromLat * sinLat);
return new Point(MathUtil.toDegreesFromRadians(Math.Asin(sinLat)), MathUtil.toDegreesFromRadians(fromLng + dLng));
}
I have multiple locations and current location, i want to find distance between my current location and other given location of google map flutter.
please provide any method or library which can easily calculate time and distance.I am Using this code but i can not find correct distance.
double _coordinateDistance(lat1, lon1, lat2, lon2) {
var p = 0.017453292519943295;
var c = cos;
var a = 0.5 - c((lat2 - lat1) * p) / 2 +
c(lat1 * p) * c(lat2 * p) * (1 - c((lon2 - lon1) * p)) / 2;
return 12742 * asin(sqrt(a));}
use https://pub.dev/packages/flutter_locations_distance package
add your multiple locations into lat and lon array and use this code
for(int i=0;i<locCount;i++){
double distance;
// Platform messages may fail, so we use a try/catch PlatformException.
try {
distance = await FlutterLocationsDistance().distanceBetween(currentLat,
currentLon, lat[i], lon[i]);
} on PlatformException {
distance = -1.0;
}
}
and for each multiple locations you can get the distance between current location and other locations.
to get your current location use https://pub.dev/packages/location package.
for the time you can use https://pub.dev/packages/stop_watch_timer package
I am building an AR application with unity and Mapbox. I have a point to represents a building. I can geolocate the point through Mapbox. I want to see this object everywhere. So, I change the size of objects according to distance.
Firstly, the code is working. But, I could not see the point really far away, 5 km away.
// Update is called once per frame
void Update()
{
// Get user location
// Latitude
x = getLocation.x1.ToString();
user_lat = Convert.ToDouble(x);
user_lat_rad = Math.PI * user_lat / 180.0; // Radian
// Longitude
y = getLocation.y1.ToString();
user_lon = Convert.ToDouble(y);
user_lon_rad = Math.PI * user_lon / 180.0; // Radian
// Change POIs sizes
distances = distance(user_lat_rad, user_lon_rad);
double s = 0.3; // size of the poi
double d = 50f; // specific distance to point (reference distance)
double size = (distances * s) / d;
float size2 = Convert.ToSingle(size);
temp = transform.localScale;
temp.x = size2;
temp.y = size2;
temp.z = size2;
transform.localScale = temp;
}
public double distance(double lat2, double lon2)
{
// Haversine Formula
// Lat2,Lon2 = User Location
// Lat1,Lon1 = POI Location
double dist1 = Sqrt((Pow(Sin((lat2 - lat1) / 2), 2)) + Cos(lat2) * Cos(lat2) * (Pow(Sin((lon2 - lon1) / 2), 2)));
double distance = 2 * r * Asin(dist1);
return distance;
}
Why I couldn't see the point far away even though object size is change? Is there any limitation for this?
As said in the comments the issue most probably is a too small value for the Camera's farClipPlane.
The furthest point relative to the camera that drawing will occur.
Any object/triangle that is further away from the Camera will not be rendered.
In the Inspector it is configured on the Camera component → Clipping Planes → Far
or using code
cameraReference.farClipPlane = XYZ;
As my question states that's I am looking for a function/formula that can calculate a distance between two points. Now I have looked at example and found great functions but none of them seem to work they all return 0 when I supply 2 sets of points. Basically I will need to pass the function the following (lat1,lon1,lat2,lon2) and get back the distance. From this distance I can check a check if another point is close by.
UPDATE
Okay so I am now using the following function,
BEGIN
DECLARE pi, q1, q2, q3 , roundedVal FLOAT ;
DECLARE rads FLOAT DEFAULT 0;
SET pi = PI();
SET lat1 = lat1 * pi / 180;
SET lon1 = lon1 * pi / 180;
SET lat2 = lat2 * pi / 180;
SET lon2 = lon2 * pi / 180;
SET q1 = COS(lon1-lon2);
SET q2 = COS(lat1-lat2);
SET q3 = COS(lat1+lat2);
SET rads = ACOS( 0.5*((1.0+q1)*q2 - (1.0-q1)*q3) );
RETURN FORMAT((6371 * rads) , 1);
END
This works fine with Kilometres, but what I am looking for is meters. So I know I have the change the numbers in that function but which ones and what to. Any help ?
I have used this webiste in the past and it has worked for me. Has lots of useful formulas and gives examples in javascript.
http://www.movable-type.co.uk/scripts/latlong.html
I'd recommend you take a look at a spacial extention to MySQL.
http://dev.mysql.com/doc/refman/5.0/en/spatial-extensions.html
If you don't fancy that, this blog might have some use to you:
http://zcentric.com/2010/03/11/calculate-distance-in-mysql-with-latitude-and-longitude/
Try this query
$qry = "SELECT *,(((acos(sin((".$latitude."*pi()/180)) *
sin((`Latitude`*pi()/180))+cos((".$latitude."*pi()/180)) * cos((`Latitude`*pi()/180))*
cos(((".$longitude."- `Longitude`)*pi()/180))))*180/pi())*60*1.1515) as distance FROM
'MyTable` WHERE distance >= ".$distance."
apply this on the values
double theta = src_longitude - dest_longitude;
double min_distance = (Math.sin(Math.toRadians(src_latitude)) * Math.sin(Math.toRadians(dest_latitude))) +(Math.cos(Math.toRadians(src_latitude)) * Math.cos(Math.toRadians(dest_latitude)) * Math.cos(Math.toRadians(theta)));
min_distance = Math.acos(min_distance);
min_distance = Math.toDegrees(min_distance);
min_distance = min_distance * 60 * 1.1515 * 1.609344;
I want to calculate the distance that users cover while walking using GPS. For example a user taps the start button and starts to walk or run than when he done he taps stop. What will be the minimum distance user has to travel to get the different lat long?
How can we do it in IPhone, asume we take Lat, long after every 0.3 sec than in the last we have a list of points?
You could do this by calculating the distance between 2 points (latitude, longitude):
(I haven't tested it):
-(double)distanceBetweenCoordinate:(CLLocationCoordinate2D)c1 andCoordinate:(CLLocationCoordinate2D)c2 {
double long1 = degreesToRadians(c1.longitude);
double lat1 = degreesToRadians(90 - c1.latitude);
double long2 = degreesToRadians(c2.longitude);
double lat2 = degreesToRadians(90 - c2.latitude);
double gamma = fabs(long1 - long2);
if (gamma > M_PI) {
gamma = 2 * M_PI - gamma;
}
double result = cos(lat2) * cos(lat1) + sin(lat2) * sin(lat1) * cos(gamma);
return acos(result) * 6366.1977; // Kilometers
};
CGFloat degreesToRadians(CGFloat degrees) {
return degrees * M_PI / 180;
};
UPDATE: Use distanceFromLocation - Calculate distance between two points instead