That's where it gets ugly really fast! A distribution such as the Dirac distribution cannot be plotted as easily as a function. JMG showed examples in this thread where the Fourier transform has a usable close form. The rest of the time you'll end up using a discrete Fourier transform calculation to display the function spectrum. Needless to say, one must be really careful about discrete sampling, windowing and aliasing effects... If you have a specific function in mind we can certainly get you started. Xavier
Attached in 2000 is a tutorial about DFT and 'fft'. The overall presentation is not final but it contains lot of information and several examples. _________DO NOT OPTIMIZE________ it will kill your box. It blocks at the definition of DFT and never stops and you can not stop calculating either ! It pushes the symbolic in corner. Please confirm you can open.
Nice worksheet, Jean. One comment about the DFT: the advantage of the DFT is that it allows to calculate spectral components at any frequency, contrary to the FFT (given a fixed number of samples). The FFT is usefull to get a full spectrum sampling in one shot. The DFT allows to focus on a particular frequency. Xavier
Merci Xavier, True, DFT is useful to have. The only problem is that it blocks dead the optimize and you have to crash the box. Like Robert says: optimize => puzzling ! In the next posting, "Mathcad usage chat" I will attach 4 work sheets saved 2000 [Hope they open correct], then in one of them optimize does such a great job !