This function returns the ray closest to the given azimuth, or the first ray of
sweep if azimuth is omitted. If closest ray is not found, function returns -1.
Syntax
ray = rsl_get_ray_from_sweep(sweep [, azimuth])
Inputs
sweep
a sweep structure.
azimuth
azimuth of ray to be returned. Azimuth values range from 0 to 360
degrees, increasing clockwise, with 0 being north.