ABSTRACT
It is common to speak of classical, as opposed to modern, signal processing methods. In this chapter we describe briefly the distinction. Then we discuss entropy maximization, eigenvector methods, and related nonlinear methods in signal processing. We first encounter infinite series expansions for functions in calculus when we study Maclaurin and Taylor series. Fourier series are usually first met in different contexts, such as partial differential equations and boundary value problems. Laurent expansions come later when we study functions of a complex variable. There are, nevertheless, important connections among these different types of infinite series expansions that we consider in this chapter.
