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.
 
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