[R-sig-Geo] convert (lat -lon) coordinates to cartesian coordinates

[Rolf Turner]

On 01/08/11 10:25, Angelo Moreno wrote:
> Hi, I have a list.In the fisrt column are the latitudes, in the second column
> are the longitudes, how could i convert this format to cartesian
> coordinates, is that possible in R?,Thanks  a lot.

It's really not that simple.  Latitude and longitude are coordinates on
the surface of a sphere.  Cartesian coordinates are coordinates on a
flat surface.  They are fundamentally incompatible. There are various
***projections*** of regions of a spherical surface onto a plain that 
provide
approximate relationships.  How good these approximations are depends on
the size and shape of the region on the spherical surface.

There may be tools in the "sp" package which could be of use to you.

     cheers,

         Rolf Turner