While Nyquist is one of the most general stability tests,
it is still restricted to linear, time-invariant(LTI) systems.
The user can independently create effects working with the Nyquist language or use the built-in ones(reverse, fraser, echo, Wah-Wah).
For an even number of input points, A[n/2]
represents both positive and negative Nyquist frequency, and is also purely real for real input.