1function dcblock_plot_transferfn(R, fs); 2% Plot the transfer function. 3% For a DC Blocking filter: H(z) = (1-1/z)/(1 - R/z) 4% Therefore the coefficients are b = [1 -1], a = [1 -R] 5b = [1 -1]; 6a = [1 -R]; 7 8f = linspace(1, fs/2, 500); 9 10semilogx(f, 20*log10(freqz(b, a, f, fs))); 11grid on 12xlabel('Frequency (Hz)'); 13ylabel('Magnitude (dB)'); 14tstr = sprintf("DC Blocking Filter Frequency Response, R = %i", R); 15title(tstr); 16 17endfunction 18