low pass filter in matlab

main.m
% define the parameters
order = 4; % filter order
fc = 1000; % cutoff frequency (Hz)
fs = 20000; % sampling frequency (Hz)

% design the filter
[b, a] = butter(order, fc/(fs/2), 'low');

% apply the filter to a signal
signal = randn(1,10000); % example signal to filter
filtered_signal = filter(b, a, signal);

% plot the signals in time domain
t = (0:length(signal)-1)/fs; % time vector
figure
plot(t, signal)
hold on
plot(t, filtered_signal)
xlabel('Time (s)')
ylabel('Signal Amplitude')
legend('Original signal', 'Filtered signal')
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