clg
t=[0:63]*2*pi/8;
% note this gives a frequency that is one of the FFT freqs
x=cos(t);
y=fft(x);
plot([1:64],2*log10(abs(y)));
v=axis;
axis([0 64 v(3) v(4)]);
title('Periodogram of X with N=64');
ylabel('LOG_10(ABS(Y^2))');
xlabel('Frequency index j');
%gtext('X = cos([1:64]*2*pi/8)');
print -deps pgram1