A numerical method for rapid computation of the coefficients in a finite Fourier transform. The method was introduced in 1965 by Tukey and the American mathematician James W. Cooley. If the (possibly complex) values of a function f(x) are known at N equally spaced points, x0, x1,⋯, xN−1, where xk = 2πk/N for k = 0, 1,⋯, N−1, the coefficients cn are such that
where .