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Tutorial
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   This chapter describes the basic usage of FFTW, i.e., how to compute
the Fourier transform of a single array.  This chapter tells the truth,
but not the *whole* truth. Specifically, FFTW implements additional
routines and flags, providing extra functionality, that are not
documented here.  Note: FFTW Reference, for more complete information.
(Note that you need to compile and install FFTW before you can use it in
a program.  Note: Installation and Customization, for the details of
the installation.)

   Here, we assume a default installation of FFTW.  In some
installations (particulary from binary packages), the FFTW header files
and libraries are prefixed with ``d'' or ``s'' to indicate versions in
double or single precision, respectively.  The usage of FFTW in that
case is the same, except that `#include' directives and link commands
must use the appropriate prefix.  Note: Installing FFTW in both single
and double precision, for more information.

   This tutorial chapter is structured as follows.  Note: Complex
One-dimensional Transforms Tutorial describes the basic usage of the
one-dimensional transform of complex data.  Note: Complex
Multi-dimensional Transforms Tutorial describes the basic usage of the
multi-dimensional transform of complex data.  Note: Real
One-dimensional Transforms Tutorial describes the one-dimensional
transform of real data and its inverse.  Finally, Note: Real
Multi-dimensional Transforms Tutorial describes the multi-dimensional
transform of real data and its inverse.  We recommend that you read
these sections in the order that they are presented.  We then discuss
two topics in detail.  In Note: Multi-dimensional Array Format, we
discuss the various alternatives for storing multi-dimensional arrays
in memory.  Note: Words of Wisdom shows how you can save FFTW's plans
for future use.

Complex One-dimensional Transforms Tutorial

Complex Multi-dimensional Transforms Tutorial

Real One-dimensional Transforms Tutorial

Real Multi-dimensional Transforms Tutorial

Multi-dimensional Array Format

Words of Wisdom