110559 Mixed Radix Fourier Transform Program Version: May 1982 Submitted by: Ian Wynne-Jones, Imperial College, London, England Operating System: Independent Source Language: FORTRAN IV-PLUS Keywords: Scientific Applications Abstract: The mixed radix Fourier transform code computes the discrete Fourier transform of a set of real or complex data points. The fast Fourier transform programs usually encountered are radix two transforms, where the number of data points is restricted to a power of two. With the mixed radix code the number of data points that can be transformed is much more flexible. In these routines the number can be a product of a power of two, three, four or five. There are two stages to the transform: firstly, the data is reordered and secondly, the arithmetic operations of the transform are performed. For speed and generality the first stage requires an additional workspace array equal in size to the input data array. Another stage is required if the input data was real. If the data is complex the real and imaginary parts are stored as FORTRAN stores them. The code is not optimized. On a PDP 11/34 with floating point processor a 1000 point transform takes 1.52 seconds. Media (Service Charge Code): Write-Up and Listing (DA), One RX01 Diskette (KA) Format: FILES-11, 600' Magnetic Tape (MA) Format: FILES-11

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