t = (1:800)/200;
S = 0.8*sin(2*pi*60*t) + 2.3*sin(2*pi*25*t);
myper(S, 200);
figure
load gong.mat;
myper(y, Fs)
%Dominat freq around 1000 and 1250
figure
load handel.mat
myper(y(1:73110), Fs)
%Dominate freq around 600 and 1200

function z = myper(x,samp)

N = length(x);
TT = N/samp; %total elapsed time
X = fft(x);
P2 = (1/N^2)*abs(X).^2; %rescale amplitude
P1 = P2(1:N/2+1);
P1(2:end-1) = 2*P1(2:end-1);
f = (0:N/2)/TT;
plot(f,P1) 
title('Periodogram of X(t)')
xlabel('freq (Hz)')
ylabel('|P1(f)|')
end