reduce noise by filtering 5 by 5 in matlab

To reduce noise in a signal by applying a moving average filter in MATLAB, you can use the movmean() function. The movmean() function computes the moving average of a vector, with a specified window size. Here's an example code to apply a 5-by-5 moving average filter to a noisy signal:

main.m
% Generate a noisy signal
t = linspace(0, 10, 1000);
x = sin(t) + 0.2 * randn(size(t));

% Apply a 5-by-5 moving average filter
y = movmean(x, 5);

% Plot the original and filtered signals
plot(t, x, 'b', t, y, 'r');
legend('Noisy signal', 'Filtered signal');
xlabel('Time');
ylabel('Amplitude');
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In the above code, t is a vector containing time samples, and x is the noisy signal. The movmean() function is used to compute a moving average of x with a window size of 5 samples. The resulting filtered signal is stored in y. Finally, the plots of original and filtered signals are displayed using the plot() function.