Add a Nyquist grid (aka Hall chart) showing M-circles and N-circles on the complex plane. Tweak Nichols grid to eliminate unnecessary use of kwargs.
Add a Nyquist grid (aka Hall chart) showing M-circles and N-circles on the complex plane. Tweak Nichols grid to eliminate unnecessary use of kwargs.

python-control/python-control,roryyorke/python-control,murrayrm/python-control