An Algol Convolution Procedure Based on the Fast Fourier Transform (Algorithm 345 [C6]) CACM October, 1969 Singleton, R. C. fast Fourier transform, complex Fourier transform, multivariate Fourier transform, Fourier series, harmonic analysis, spectral analysis, orthogonal polynomials, orthogonal transformation, convolution, auto covariance, autocorrelation, cross-correlation, digital filtering, permutation 3.15 3.83 5.12 5.14 CA691009 JB February 15, 1978 3:17 PM 1837 5 1837 1837 5 1837 1837 5 1837