How can I get the 2 highest peaks ?

1)How can I get the 2 peaks from the picture below? Because these commands gives me the only the highest.

[gpeakG1,fpeakG1] = getPeakGain(G1);
gpeakG1_dB = 20*log10(gpeakG1);

Answer 1

[Star Strider]

I would use the bode function with three output arguments, then use findpeaks with the ‘mag’ and ‘wout’ arguments:

[mag,phase,wout] = bode(sys);
[pks,locs] = findpeaks(mag, wout);

Add the name-value pair arguments you need to get the result you want. The findpeaks function has considerable flexibility, but how much depends on your version of MATLAB, so be sure to read the relevant documentation for your version.

[Bob]

Thanks for your answer,

[mag,phase,wout] = bode(G1);
[pks,locs] = findpeaks(mag, wout);

I got this error:

Error using findpeaks
Expected Y to be a vector.

I have got Matlab 2015a

[Star Strider]

You have a SISO system, so adding a squeeze call will work:

[pks,locs] = findpeaks(squeeze(mag), wout);

[Bob]

Thank you it works.

[Star Strider]

My pleasure.

Answer 2

[Image Analyst]

For #2, did you take a look at findpeaks()? (Requires the Signal Processing Toolbox.)