Sorting of locations ref. nearest location with flutter
Locations
Sorting of locations ref. nearest location.
Sort locations with nearest distance
How it works?
- Get user's current location
- Compare with other destinations
- Sort according the nearest
There are two ways to compare distance
Personally, I like Haversine Formula and have been using it.
Algorithm 1
Use Havesine Formula.
Haversine Formula
double 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;
}
double deg2rad(deg) {
return deg * (Math.pi/180);
}
Algorithm 2
Use inbuilt distance comparision function provided by Geolocater.
Geolocator.distanceBetween(source.latitude,source.longitude, destination.latitude,destination.longitude);
Assumption"
- You are in Google Plex (37.422,-122.084)
Destinations:
- Destination(37.4274684,-122.1698161, "Standford University"),
- Destination(37.4083327,-122.0776016, "Taco Bell"),
- Destination(37.4259071,-122.1095606, "Ramos Park"),
- Destination(37.8711583,-122.336457, "Bekerly"),
- Destination(37.7586968,-122.3053474, "Oakland"),
- Destination(37.4420794,-122.1432758, "Palo Alto"),
- Destination(37.5206515,-122.064364, "New wark")
Output:
| Haversine Algorithm | Geolocator Algorithm |
|---|---|