matlab - Remove Known Harmonic from from Frequency Response Function -

i have input sine wave in time domain frequency of 10hz. trying code in matlab develop frequency response function 2dof modal analysis problem.

in output, there dominating peak @ 10hz, due input harmonic wave

question:

which best way remove known harmonic disturbance response(output) in matlab?

also, should when disturbing harmonic not known?

fs=1/dt; nfft = 2 ^ nextpow2 (l);                       %l length of signal y = fft (output_time(1,:), nfft) / l;          %response in time domain frequency domain x=fft(input_time,nfft)/l;                      %input in time frequency domain f = fs / 2 * linspace (0,1, nfft / 2 + 1);     %frequencies output_frequency=2 * abs (y (1: nfft / 2 + 1)); input_frequency=2 * abs (x (1: nfft / 2 + 1)); frf=(y(1: nfft / 2 + 1)./x(1: nfft / 2 + 1));  %frequency response functions 

thanks suggestions;i found answer required.

i used band stop filter solve problem:

order=2; lowfreq=9.5; hifreq=10.5; [b,a] = butter(order, [lowfreq hifreq]/(fs/2), 'stop'); filtered_response = filter(b,a,u(1,:));