
A command to compute the spectrum of the selected Polynomial objects.
We calculate the spectrum by evaluating the polynomial at regularly spaced points z_{k} on the upper half of a circle with radius r = 1 in the complex plane. The upperhalf of the unit circle, where k·φ is in the interval [0, π], will be mapped to frequencies [0, Nyquist frequency] in the spectrum.
The complex values z_{k} (k=1..numberOfFrequencies) are defined as:
z_{k} = r e^{i k φ}, where, 
φ = π / (numberOfFrequencies – 1) and r = 1. 
© djmw, June 16, 1999