Given GPS coordinates, it is often useful to be able to plot the data on a Cartesian grid. The GPS2Cart.m function takes N latitude and longitude coordinates and returns N (x,y) coordinates in the first quadrant of a Cartesian grid (i.e. all x, y>=0).
WARNING: I have been using this for coordinates separated by a few km, and I believe the program does not work well for coordinates with larger separations (e.g. the scale of continents), due to the system being non-Euclidian.
New function Cart2GPS.m which takes a GPS origin and maps (x,y) coordinates to GPS. Again, assuming distances are Euclidian.
Inspired by: zoharby/plot_google_map