%濾波前資料

t = 0:0.01:10;

f=5*sin(2*pi*20*t)+5*sin(2*pi*60*t);

%濾波器設計

Fpass = 1; % Passband Frequency

Fstop = 50; % Stopband Frequency

Apass = 1; % Passband Ripple (dB)

Astop = 60; % Stopband Attenuation (dB)

Fs = 2000; % Sampling Frequency

h = fdesign.lowpass("fp,fst,ap,ast", Fpass, Fstop, Apass, Astop, Fs);

Hd = design(h, "equiripple", ...

"MinOrder", "any", ...

"StopbandShape", "flat");

%f2濾波後的資料

f2 = filter(Hd,f);

%對比圖

plot(t,f,"b",t,f2,"r");