CombSweepConfig from_comb doesn't work with a single tone

[JennySmith888]

in from_comb here,

steps = np.linspace(0, tones[1] - tones[0], points, endpoint=False) / 1e6 steps_overlap = steps[:overlap] + (tones[1] - tones[0]) / 1e6 steps = np.concatenate((steps, steps_overlap))

Throws an index error when there's only a single tone. Should a hypothetical user use from_bandwidth instead? How should from_comb behave for a single tone?

[ld-cd]

Whoops I should give a better error message there, user should use from_bandwidth here because the idea with from comb is it should sweep from one tone to the adjacent the tone with a user specified number of points to get S21. Don't close this yet, I will close it out with a doc fix.

[ld-cd]

If you want a single sided sweep like com sweep over say 10MHz like combsweep provides you can construct it with SweepConfig(np.linspace(0, 10, 1024), waveform)