[talk-au] Calculate tile numbers?

[Brent Easton]

Hi Ben,

>*********** REPLY SEPARATOR ***********
>
>On 13/01/2008 at 6:04 PM Ben Kelley wrote:
>Hi.
>
>Does anyone know the formula to convert lat/long to tile numbers at a
>given zoom? I remember reading it somewhere, but couldn't find it.
>
>It seems that at zoom 0 there is a single tile (256x256) covering the
>whole world (-90 to +90 and -180 to +180), and then at zoom n+1 the tile
>size is 1/2 as big (lat and long, so 1/4 really) as at the previous zoom
>level. Is that correct? If so I could probably work out the formula
>myself. 

Yes. That's how it works. 



____________________________________________________________
Brent Easton                       
Analyst/Programmer                               
University of Western Sydney                                   
Email: b.easton at uws.edu.au