Nyquist plotter - by Michael Rans
To perform Nyquist plots, you need to have a function of s. Type: scs/nyquist(func,wmin,wmax)
Type your command as this example: nyquist((s+2)/((s+1)(s^2+2s+4)))
In Nyquist plots, the x axis is real(s). The y axis is imag(s). (s=jw)
Sometimes you may get an error about window parameters. Try altering the scale of the axes. To do this, press the APPS button and go to Window Editor.
The step size, tstep and the minimum and maximum values of t, tmin and tmax, with t being w (s=jw) may need to be altered. This can be achieved from the Window Editor as described above.