1 files changed, 22 insertions, 1 deletions
diff --git a/src/helper.js b/src/helper.js
index 3bdbf7e..2242d91 100644
--- a/src/helper.js
+++ b/src/helper.js
@@ -43,4 +43,25 @@ export function timeConverter(UNIX_timestamp) {
 
 function formatInt(num) {
     return ("00" + num).slice(-2)
-}
-\ No newline at end of file
+}
+
+export function calcCrow(lat1, lon1, lat2, lon2) 
+    {
+      var R = 6371; // km
+      var dLat = toRad(lat2-lat1);
+      var dLon = toRad(lon2-lon1);
+      var lat1 = toRad(lat1);
+      var lat2 = toRad(lat2);
+
+      var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
+        Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2); 
+      var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
+      var d = R * c;
+      return d;
+    }
+
+    // Converts numeric degrees to radians
+    function toRad(Value) 
+    {
+        return Value * Math.PI / 180;
+    }
+\ No newline at end of file