%% Nichols Response with Nichols Grid Lines
% Plot the Nichols response with Nichols grid lines for the following system:
% H(s) = \frac{{ - 4{s^4} + 48{s^3} - 18{s^2} + 250s + 600}}{{{s^4} +
% 30{s^3} + 282{s^2} + 525s + 60}}.

H = tf([-4 48 -18 250 600],[1 30 282 525 60]);
nichols(H)
ngrid

% The context menu for Nichols charts includes the Tight option under Zoom. You can use this option to clip unbounded branches of the Nichols chart.
% Copyright 2015 The MathWorks, Inc.