%% Signal-to-Noise Ratio of Sinusoid
% Compute the SNR of a 2.5 kHz sinusoid sampled at 48 kHz. Add white noise with variance 0.001².

Fi = 2500;
Fs = 48e3;
N = 1024;
x = sin(2*pi*Fi/Fs*(1:N)) + 0.001*randn(1,N);
SNR = snr(x,Fs)

%
% Plot the spectrum and annotate the SNR.

snr(x,Fs);

% Copyright 2012 The MathWorks, Inc.