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<TITLE>Data Structures and Algorithms: Fast Fourier Transforms</TITLE>
<META name="description" content="Data Structures and Algorithms Course Notes,
PLDS210 University of Western Australia">
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<FONT FACE=helvetica SIZE=+1><I>Data Structures and Algorithms</I></FONT>
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<TR><TD><FONT FACE=helvetica SIZE=+2><B>12 Fast Fourier Transforms</B></FONT>
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<P>
Fourier transforms have wide application in scientific and
engineering problems,
for example, they are extensively used in signal processing to
transform a signal from the time domain to the frequency
domain.
<P>
Here, we will use them to generate an efficient solution to
an apparently unrelated problem - that of multiplying two
polynomials.
Apart from demonstrating how the Fast Fourier Transform
(FFT)
algorithm calculates a Discrete Fourier Transform and
deriving its time complexity,
this approach is designed to reinforce the
following points:
<UL>
<LI> 'Better' solutions are known to many problems
for which, intuitively, it would not appear possible to
find a better solution.
<LI> As a consequence,
unless you have read extensively in any problem area
already,
you should consult the literature before attempting to
solve any numerical or data processing problem
presented to you.
</UL>
<P>
Because of the limitations of HTML in handling
mathematical equations, the notes for this section
were prepared with LaTeX and are available as a
<A HREF="fft.ps" tppabs="http://www.ee.uwa.edu.au/~plsd210/ds/latex/fft.ps">PostScript file</A>.
<P>
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Continue on to <A HREF="hard.html" tppabs="http://www.ee.uwa.edu.au/~plsd210/ds/hard.html">Hard Problems</A></TD>
<TD>Back to the <A HREF="ds_ToC.html" tppabs="http://www.ee.uwa.edu.au/~plsd210/ds/ds_ToC.html">Table of Contents</A>
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<SMALL>
© <A HREF=mailto:morris@ee.uwa.edu.au>John Morris</A>, 1998
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