How to set Zoom Level in android Map v2 on the basis of Kilometers selected by User?

Question

• I am using a mapview in which by default it shows current location.
• I am using a seekbar to control zoom level based on Kilometers divided into 10,20,30,50...km.
• How to zoom in or zoom out (in Kilometers) map when user touches the seek bar.

Answer 1

Try to use this formula:

zoomLevel = 19 - Math.log(altitudeKm * 5.508);

It is not going to be 100% accurate since map is 2D representation of 3D world. Thus there is no such thing as 'view altitude'. Anyways I tried to play a bit with it and it looks close enough. :)

Taken from here. Bing maps use the same Mercator projection as android map v2, so basic math should be the same