True units along the axes when plotting the DFT

Abstract

As already mentioned above, the DFT is often used as a tool for the numerical calculation of the Fourier transform (the frequency spectrum) of a given continuous function. For this end, the original continuous function in question must be sampled, and the resulting N-element array (or in the MD case, N N-element array) is fed as input to the DFT. The resulting N-element (or N N-element) output array contains the discrete counterpart of the desired frequency spectrum, and after the appropriate reorganization (see Chapter 3) it can be plotted to illustrate graphically the resulting spectrum.