make a plot of the first second of the raw data in matlab

Assuming the raw data is stored in a variable called raw_data, you can do the following:

main.m
Fs = 1000; % Sampling frequency in Hz
N = Fs; % Duration of plot in samples
t = (0:N-1)/Fs; % Time vector in seconds
figure;
plot(t, raw_data(1:N));
xlabel('Time (s)');
ylabel('Amplitude');
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This code will make a plot of the first N = Fs samples (i.e. the first second) of the raw_data variable. The t variable is constructed to be a time vector in seconds that is the same length as the raw_data samples, and the plot function is used to plot the data against the time vector. The xlabel and ylabel functions are used to label the axes of the plot.