Data must be provided in decimal degrees (e.g. 162.546). Longitude values west of the prime meridian are 0 to -180.
Latitude values south of the equator are 0 to -90. This function is primarily used internally in the GPStable and
GeoReference functions.
# NOT RUN {##Distance from New York to Los Angeles given Latitude and Longitude of New York and Los Angeles.Howfar<-CalcDistance(40.7697,-73.9735,34.0522,-118.2428)
Howfar
# }