Change marker width in bode plot

By default, the marker width of the bode plot is very large. There is an option to change the line width but no option to change the marker width? How can I change it ?

Answer 1

[Star Strider]

The bode function doesn’t accept many options with respect to its plots. The easiest way to do what you want is to request at least the first three outputs of the bode function, and then plot them using subplot and plot. The plots are the same as any other plot object:

[mag,phase,wout] = bode(sys);
subplot(2,1,1)
plot(wout, mag)
subplot*2,1,2)
plot(wout, phase)

Use ‘20*log10(mag)’ to plot the magnitude in decibels, and semilogx instead of plot to make the plot look like those bode produces on its own:

[mag,phase,wout] = bode(sys);
subplot(2,1,1)
semilogx(wout, 20*log10(mag))
subplot*2,1,2)
semilogx(wout, phase)

[sarita jain]

I did this

sys = tf([1],[1 3 2])
[mag,phase,wout] = bode(sys);
subplot(2,1,1)
plot(wout, mag)
subplot(2,1,2)
plot(wout, phase)

It is showing an error as follows

 Error using plot
Data cannot have more than 2 dimensions.
Error in Delitaf (line 4)
plot(wout, mag)

[Star Strider]

Since ‘mag’ and ‘phase’ are 3D arrays, use the squeeze function to remove the singleton dimension in ‘mag’ and ‘phase’ in a SISO system:

[mag,phase,wout] = bode(sys);
magv = squeeze(mag);
phasev = squeeze(phase);

figure(1)
subplot(2,1,1)
semilogx(wout, 20*log10(magv))
ylabel('Magnitude (dB)')
subplot(2,1,2)
semilogx(wout, phasev)
xlabel('Frequency (r/s)')
ylabel('Phase (°)')

[sarita jain]

I need to have multiple bode plots on a single graph. How and where would I use

hold on

in the above case

[Star Strider]

I am not certain what you want to do.

One possibility:

figure(1)
subplot(2,1,1)
semilogx(wout1, 20*log10(magv1))
hold on
semilogx(wout2, 20*log10(magv2))
semilogx(wout3, 20*log10(magv3))
hold off
ylabel('Magnitude (dB)')

subplot(2,1,2)
semilogx(wout1, phasev1)
hold on
semilogx(wout2, phasev2)
semilogx(wout3, phasev3)
hold off
xlabel('Frequency (r/s)')
ylabel('Phase (°)')

[sarita jain]

Thanks a lot. I wanted to do this only.

[Star Strider]

As always, my pleasure.