I have added Chapter 5 which covers DFT and DTFT and a little bit about FFT. The tutorial has most of the Matlab code used to generate the graphs. In the links page, I have also added the sites I referred to. Most of them are very good.
Once you dive into the topic, you realize how simple on hand but then so complex at the same time, kind of like Life, I guess. The next topic on the list is Windows. Use of Windows is almost mandatory when doing DFT on real signals. So understanding how to use them is as important as the DFT itself.
April 3, 2013