### FFT of a Not-So-Simple Sinusoid

Now let's increase the frequency in the above example by one-half of a bin:% Example 2 = Example 1 with frequency between bins f = 0.25 + 0.5/N; % Move frequency up 1/2 bin x = cos(2*pi*n*f*T); % Signal to analyze X = fft(x); % Spectrum ... % See Example 1 for plots and such

*periodic extension*(§7.1.2) of the time waveform:

% Plot the periodic extension of the time-domain signal plot([x,x],'--ok'); title('Time Waveform Repeated Once'); xlabel('Time (samples)'); ylabel('Amplitude');The result is shown in Fig.8.3. Note the ``glitch'' in the middle where the signal begins its forced repetition.

**Next Section:**

FFT of a Zero-Padded Sinusoid

**Previous Section:**

FFT of a Simple Sinusoid