Program for distance between two points on earth

 

การคำนวณระยะทางระหว่างจุดสองจุด( latitude, longitude)

หาค่าละติจูดเป็นเรเดียน:

    lat = Latitude / (180/pi)  หรือ

    lat = Latitude / 57.29577951

หาค่าลองจิจูดเป็นเรเดียน:

    long = Longitude / (180/pi)  หรือ

    long = Longitude / 57.29577951

<script>

// JavaScript program to calculate Distance Between

// Two Points on Earth

function distance(lat1, lat2, lon1, lon2)

{

// The math module contains a function

// named toRadians which converts from

// degrees to radians.

lon1 = lon1 * Math.PI / 180;

lon2 = lon2 * Math.PI / 180;

lat1 = lat1 * Math.PI / 180;

lat2 = lat2 * Math.PI / 180;

// Haversine formula 

let dlon = lon2 - lon1; 

let dlat = lat2 - lat1;

let a = Math.pow(Math.sin(dlat / 2), 2)

+ Math.cos(lat1) * Math.cos(lat2)

* Math.pow(Math.sin(dlon / 2),2);

let c = 2 * Math.asin(Math.sqrt(a));

// Radius of earth in kilometers. Use 3956 

// for miles

let r = 6371;

// calculate the result

return(c * r);

}

// Driver code 

let lat1 = 53.32055555555556;

let lat2 = 53.31861111111111;

let lon1 = -1.7297222222222221;

let lon2 = -1.6997222222222223;

document.write(distance(lat1, lat2, lon1, lon2) + " K.M");

</script>