Hi Sam,
You can add a vertical line to the magnitude graph while hiding the phase graph by adding the line to the correct axes.
You can refer to the following code snippet for reference:
% Plot the data with phase hidden
plot(M3f, opt);
% Get handles to the axes
ax = gca; % Get current axes, assuming it's the magnitude plot
% Add a vertical line to the magnitude plot
xline(ax, 5);
% Customize the plot
title(ax, 'Frequency Graph');
legend(ax, {'data1', 'data2', 'data3', 'data4'});
I hope this resolves the issue!
