Maps API Office Hours (Sydney) - Google Moderator.
Hash map. Vincenty ellipsoidal formula. For the benefit of the terminally obsessive (as well as the genuinely needy), Thaddeus Vincenty (‘TV’) devised formulae for calculating geodesic distances between a pair of latitude/longitude points on the earth’s surface, using an accurate ellipsoidal model of the earth.
When I looked up the references (‘Direct and Inverse Solutions of Geodesics on the Ellipsoid with application of nested equations’), I discovered to my surprise that while the mathematics is utterly beyond me, it is actually quite simple to program. Vincenty’s formula is accurate to within 0.5mm, or 0.000015″ (!) , on the ellipsoid being used. Calculations based on a spherical model, such as the (much simpler) Haversine, are accurate to around 0.3% (which is still good enough for most purposes, of course). Haversine formula. 21.21258,72.820816. Screen reader users: click here for plain HTML +You Search Images.
Maps Javascript API V3 Reference - Google Maps JavaScript API v3. Release Version Last updated Monday, February 17, 2014 This reference documents version 3.15 (the release version) of the Maps Javascript API released November 15, 2013.
This release version of the API is a feature-stable version of the API whose interfaces are guaranteed to remain as documented within these pages until this version is retired.