% kdiff.m - lowpass FIR differentiator design using Kaiser window.%% h = kdiff(fs, fc, Df, A)%% fc = cutoff frequency in [Hz]% Df = transition width in [Hz]% A = stopband ripple attenuation in [dB]% ddiff(wc, N) = ideal FIR differentiatorfunction h = kdiff(fs, fc, Df, A)wc = 2 * pi * fc / fs;DF = Df / fs;[alpha, N] = kparm(DF, A);h = ddiff(wc, N) .* kwind(alpha, N);