MATLAB: Peak Value from bodemag plot

bodebodemagbodemag plotbodeplot

I am trying to calculate the peak value of the bodemag plot. Attached is the code I am trying to use 
[gpeak,fpeak] = getPeakGain(SS_1)
gpeak_dB = 20*log10(gpeak);
However that doesn't seem to work for bodemag plots, only for bode plots because it isn't giving me the correct peak for the plot attached.
How do I calculate the peak of a bodemag plot?

Best Answer

Try this: 
F = openfig('untitled.fig');
getF = get(F);
Lines = findobj(F, 'Type','Line');
for k = 1:numel(Lines)
    X{k} = Lines(k).XData;
    Y{k} = Lines(k).YData;
    [Ymax,Idx] = max(Y{k});
    FM{k,:} = [X{k}(Idx) Ymax  Idx];
end
MagFreq = array2table(cell2mat(FM), 'VariableNames',{'Frequency','Magnitude','Index'})
producing: 
MagFreq =
    Frequency     Magnitude     Index
    _________    ___________    _____
        NaN              NaN      1  
        NaN              NaN      1  
      1e-20       1.2722e-14      1  
      1e-20                0      1  
      1e-20       1.2722e-14      1  
      1e-20       2.5444e-14      1  
      1e-20                0      1  
      1e-20       1.7358e-14      1  
     1.6051          0.52101     35  
      1e-20      -2.5073e-14      1  
     1.3159         0.062431     32  
      1e-20      -2.5073e-14      1
It is not difficult to extract the values, however it is definitely not straightforward.
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