Hi everyone,
I have a big SS (1 input, 1 output, 186 states), and I try to create the Bode plot. This all works if I use the following code:
h_bode = bodeoptions;h_bode.Xlim = [1 2000];h_bode.FreqUnits = 'Hz';h_bode.MagUnits = 'abs';h_bode.MagScale = 'log';h_bode.PhaseWrapping = 'on';h_bode.phaseVisible = 'on';h_bode.Grid = 'on';wmin = log10(0.001)*2*pi;wmax = log10(2000)*2*pi;npoints = 10000;figure('name','SS Bode Plant P(s)');w = logspace(wmin,wmax,npoints);h_bode.MagUnits = 'abs';bodeplot(P,w,h_bode);set(findobj('Type','line'),'Linewidth',2)title('Bode Diagram: Plant P(s) (dp2np)');
However, when I use "
h_bode.MagUnits = 'dB';
it gives the warning 'negative data ignored'.
Do I need to do with the State Space model before giving it as input for 'bodeplot'? Or am I missing something?
Thanks in advance,
Thijs
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