[R-sig-Geo] Dividing World Map

[Barry Rowlingson]

On Mon, Oct 1, 2012 at 8:09 AM, Massimiliano Ruocco <ruocco at idi.ntnu.no> wrote:
> Dear all,
> i would like to divide the world map in grid of equal dimension (example
> quad of 10kmx10km). Is it correct to use the UTM coord instead of
> lat/lon ones? Is there any drawback on doing that?
>
> IS there any existing routine doing it?

 Since we figured out that the earth isn't flat we've known its
impossible. You can't divide a sphere into a grid like that - what are
you going to do at the poles?

 You can project small parts to coordinates such as UTM and divide
into a regular square grid in those coordinates, but even those aren't
perfect, and get less perfect nearer the poles, at which point they
are completely wrong...

I think UTM zones typically have a max latitude they should be used
at, so as long as you don't care about polar bears and penguins you
should be okay...

Barry