https://www.mathworks.com/help/signal/ug/remove-the-60-hz-hum-from-a-signal.html

load openloop60hertz, openLoop = openLoopVoltage;

Fs = 1000;

t = (0:length(openLoop)-1)/Fs;

plot(t,openLoop)

ylabel('Voltage (V)')

xlabel('Time (s)')

title('Open-Loop Voltage with 60 Hz Noise')

grid

d = designfilt('bandstopiir','FilterOrder',2, ...

'HalfPowerFrequency1',59,'HalfPowerFrequency2',61, ...

'DesignMethod','butter','SampleRate',Fs);

fvtool(d,'Fs',Fs)

buttLoop = filtfilt(d,openLoop);

plot(t,openLoop,t,buttLoop)

ylabel('Voltage (V)')

xlabel('Time (s)')

title('Open-Loop Voltage')

legend('Unfiltered','Filtered')

grid

[popen,fopen] = periodogram(openLoop,[],[],Fs);

[pbutt,fbutt] = periodogram(buttLoop,[],[],Fs);

plot(fopen,20*log10(abs(popen)),fbutt,20*log10(abs(pbutt)),'--')

ylabel('Power/frequency (dB/Hz)')

xlabel('Frequency (Hz)')

title('Power Spectrum')

legend('Unfiltered','Filtered')

grid

Plot the power spectrum of the example, but do so with the range reduced to: 0-20 Hz. provide the code and graph

[popen, fopen] 0 = periodogram ( openLoop,[],[],Fs); perioogrm(buttLoo, [, [],F); 0 2 butt,fbutt] plot (fopen, 20xlog10 (abs (popen)),fbutt,20*log10 (abs (pbutt)),"-') ylabel('Power/frequency (dB/Hz)') xlabel( 'Frequency (Hz) title( 'Power Spectrum) legend 'Unfiltered, 'Filtered') grid Power Spectrum _Unfiltered _ _ -Filtered 40 -60 80 -100 -120 -140 0 50 100 150 200 250 300 350 400 450 500 Frequency (Hz) [popen, fopen] 0 = periodogram ( openLoop,[],[],Fs); perioogrm(buttLoo, [, [],F); 0 2 butt,fbutt] plot (fopen, 20xlog10 (abs (popen)),fbutt,20*log10 (abs (pbutt)),"-') ylabel('Power/frequency (dB/Hz)') xlabel( 'Frequency (Hz) title( 'Power Spectrum) legend 'Unfiltered, 'Filtered') grid Power Spectrum _Unfiltered _ _ -Filtered 40 -60 80 -100 -120 -140 0 50 100 150 200 250 300 350 400 450 500 Frequency (Hz)