pkg load signal;

f = 20;
Ts = 0.001;
fs = 1/Ts;
fnyq = fs/2;
interval = [0:Ts:5];
nbsamples = length(interval);
df = fs/nbsamples;

sin20 = sin(2*pi*f*interval);
FFT = abs(fft(sin20));

RMZ = remez(8, [101*df/fnyq 103*df/fnyq], [FFT(101) FFT(103)], "differentiator");
