In Chapter 4, several analytical functions and their geometric representations were discussed. This chapter takes one step further, discuss series of analytical functions. Part of Chapter 6 shows that an analytical function can be used to model an experimental data set by adjusting its parameters. Due to the flexibility of series, they are often very good at modeling data. Among all types of series, we certainly cannot ignore Fourier series and fast Fourier transformation (FFT) in crystallography.
7.1 Base Class