clg t=[0:63]*2*pi/8; % note this gives a frequency that is one of the FFT freqs x=exp(i*t); y=fft(x); plot([1:64],2*log10(abs(y))); v=axis; axis([0 64 v(3) v(4)]); xlabel('Frequency index j'); ylabel('LOG_10(ABS(Y^2))'); print -deps pgram0