More advanced stuff

Google Maps API Tutorial

Distances

The API provides a function that calculates the straight line distance between two points.

To use it to calculate the distance in metres between two GLatLng objects, we writeP1.distanceFrom(P2).

That returns a number with the maximum number of decimal places that your Javascript interpreter supports, which is somewhat excessive so you might want to use the .toFixed(N) method to round the result to N decimal places.

Here’s an example of the code in use.

For the bearing, I’ve used an algorithm by Vincenty which is claimed to produce better results than using atan2() when the distances are large.

Advertisements