Sweep2ticks.m

Converts offset-sweep-npoints specification to axis ticks in Hz. Syntax:

              axis_hz=sweep2ticks(offs,sweep,npoints)

Parameters:

      offs     - offset from carrier frequency, Hz

     sweep     - sweep width, Hz

   npoints     - number of points in the spectrum

The function returns the frequency axis of the spectrum, suitable for use in functions like plot().