How can I set linewidth directly in bode command?

I can draw a bode plot as below

sys = tf(4,[1 0.5 4]);
figure(1), bode(sys), grid on;

Now, I would like to change some options in the Bode plot.

I can set the options through 'bodeoptions' as below.

sys = tf(4,[1 0.5 4]);
options = bodeoptions;
options.FreqUnits = 'Hz';
options.Title.FontSize = 14;
options.XLabel.FontSize = 14;
options.YLabel.FontSize = 14;
options.TickLabel.FontSize = 14;
figure(2), bode(sys, options), grid on;

But I can't find the option to set the linewidth of the bode plot.

How can I do that?

Answer 1

[Birdman]

You can try semilogx. See the following code:

sys=tf(4,[1 0.5 4]);
[mag,phase,wout] = bode(sys);
Mag=20*log10(mag(:));Phase=phase(:);
figure(1);semilogx(wout,Mag,'LineWidth',5);grid on;
figure(2);semilogx(wout,Phase,'LineWidth',1);grid on;

[byungkeuk cho]

Thank you for your answer.

I thought of this way but I wanted to know if I can do the same thing with bode options.

Really appreciate it though.

Answer 2

[Star Strider]

It is possible to do this without getting the outputs from bode and doing separate plots, however it requires some fairly extensive ‘handle diving’:

sys = tf(4,[1 0.5 4]);
figure(1)
bode(sys) 
grid
Fh = gcf;                                                   % Handle To Current Figure
Kids = Fh.Children;                                         % Children
AxAll = findobj(Kids,'Type','Axes');                        % Handles To Axes
Ax1 = AxAll(1);                                             % First Set Of Axes
LinesAx1 = findobj(Ax1,'Type','Line');                      % Handle To Lines
LinesAx1(2).LineWidth = 5;                                  % Set ‘LineWidth’
Ax2 = AxAll(2);                                             % Second Set Of Axes
LinesAx2 = findobj(Ax2,'Type','Line');                      % Handle To Lines
LinesAx2(2).LineWidth = 5;                                  % Set ‘LineWidth’

Experiment to get different results.

[byungkeuk cho]

Thank you for your answer.

It looks a bit complicated as you said.

Anyway, I will keep it as another option.

[Star Strider]

My pleasure.

This is the only way I am aware of to change the linewidths (or any other options) in the Control System Toolbox and System Identification Toolbox graphics functions.

Answer 3

[Marcelo Moraes]

fig = gcf;
obj = findobj(fig,'Type','hggroup');
for idx = 1:numel(obj)
    for jdx = 1:numel(obj(idx).Children)
        obj(idx).Children(jdx).LineWidth = 2;
    end
end

Answer 4

[Siddharth Jawahar]

Hello Byungkeuk,

Here is an example script to demonstrate how you can adjust the linewidth of a bode plot.

sys = tf([4, 1], [0.5, 4]);  % Define the system transfer function
figure(1);
[mag,phase,wout] = bode(sys);  % Store Bode plot data
h = bodeplot(sys);             % Plot Bode diagram
grid on;

% Get the line handles
hline = findall(gcf, 'type', 'line');

% Set the linewidth
set(hline, 'LineWidth', 2); % Change 2 to your desired linewidth

Hope this helps,

Sid