Unused Functions

[max-anu]

These are some functions I don't think are used, and @OKaluza you might want to remove them (or maybe not).

• lonlat_grid - this function is empty
• magnitude
• uv_to_pixel
• lonlat_to_pixel
• draw_lonlat_grid (This might be useful in the future)

[OKaluza]

These are utility funcitons that are not always used internally in the library, but are used in external code at some point.