Fourier analysis uses a Fourier transform to convert a time series or other form of seqence into a series of frequency components and then performs further mathematical anaysis on this frequency domain data. Fourier analysis is used frequently as part of time-series analysis and as an early stage of a {[speach recognition}}. Although most commonly encountered for time-series data, there are also 2D spatial and hgher-order equivalents.
Used on Chap. 6: page 124; Chap. 19: page 472
Digitally produced spectrogram of a male voice saying `nineteenth century' (source: Wikipedia) -- a sectrogram is a form of Fourier transform
