control.nichols_grid

control.nichols_grid(cl_mags=None, cl_phases=None, line_style='dotted', ax=None, label_cl_phases=True)[source]

Nichols chart grid.

Plots a Nichols chart grid on the current axis, or creates a new chart if no plot already exists.

Parameters

  • cl_mags (array-like (dB), optional) – Array of closed-loop magnitudes defining the iso-gain lines on a custom Nichols chart.

  • cl_phases (array-like (degrees), optional) – Array of closed-loop phases defining the iso-phase lines on a custom Nichols chart. Must be in the range -360 < cl_phases < 0

  • line_style (string, optional) – Matplotlib linestyle

  • ax (matplotlib.axes.Axes, optional) – Axes to add grid to. If None, use plt.gca().

  • label_cl_phases (bool, optional) – If True, closed-loop phase lines will be labelled.

Returns

  • cl_mag_lines (list of matplotlib.line.Line2D) – The constant closed-loop gain contours

  • cl_phase_lines (list of matplotlib.line.Line2D) – The constant closed-loop phase contours

  • cl_mag_labels (list of matplotlib.text.Text) – mcontour labels; each entry corresponds to the respective entry in cl_mag_lines

  • cl_phase_labels (list of matplotlib.text.Text) – ncontour labels; each entry corresponds to the respective entry in cl_phase_lines