Displaying a GPX track

src/lib/geo.ts

@@ -10,13 +10,14 @@ export interface geoPoint {
 
 // cf https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#ECMAScript_(JavaScript/ActionScript,_etc.)
 export const lon2tile = (lon: number, zoom: number) => {
-  return ((lon + 180) / 360) * Math.pow(2, zoom);
+  return ((Number(lon) + 180) / 360) * Math.pow(2, zoom);
 };
 export const lat2tile = (lat: number, zoom: number) => {
   return (
     ((1 -
       Math.log(
-        Math.tan((lat * Math.PI) / 180) + 1 / Math.cos((lat * Math.PI) / 180)
+        Math.tan((Number(lat) * Math.PI) / 180) +
+          1 / Math.cos((Number(lat) * Math.PI) / 180)
       ) /
         Math.PI) /
       2) *