ValueError raised for certain systems with nyquist_response #1103
Description
For certain systems, when "indent_direction" is set to 'none', a ValueError is thrown on
python-control/control/freqplot.py
Line 1456 in 71bd731
Code to reproduce:
import sympy as smp
from control import tf, nyquist_response
s = tf('s')
tf1 = ((1 + 5/s)/(1 + 0.5/s))**2 # Double-Lag-Compensator
nyquist_response(tf1, warn_encirclements=False, indent_direction='none')