Howto generate non linear tones ?

The first one is easy using “Nyquist” scripting.

Apply this code via the “Nyquist Prompt” effect (See: Nyquist Prompt - Audacity Manual)

(setf bias 0.5)
(setf hz 100)
(setf amplitude 0.8)
(scale amplitude (osc-pulse hz bias))

  • “bias” controls the pulse width and should be between -1 and +1, giving a pulse width from 0% (always at -1) to 100% (always at +1). When bias is zero, a square wave is generated.
  • “hz” controls the frequency.
  • “amplitude” controls the amplitude (0 to 1)

For more complex examples, as Trebor wrote, see this plug-in: Expression Generator - #2 by steve
It is a “Nyquist plug-in”.
Installation instructions for Nyquist plug-inson Linux: