 Fast Fourier transform

The Fast Fourier Transform (FFT) is an algorithm that computes the Discrete Fourier Transform (DFT) and its inverse efficiently. The DFT is a mathematical transformation used to analyze the frequency content of discrete signals, transforming a sequence of complex numbers into another sequence of complex numbers. The basic idea is to express a discrete signal as a sum of sinusoids, which can provide insights into the signal's frequency characteristics.

An efficient algorithm to calculate the discrete Fourier transform.