96 lines
4.0 KiB
HTML
96 lines
4.0 KiB
HTML
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<!-- This manual is for FFTW
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(version 3.3.10, 10 December 2020).
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Copyright (C) 2003 Matteo Frigo.
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Copyright (C) 2003 Massachusetts Institute of Technology.
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<title>Interleaved and split arrays (FFTW 3.3.10)</title>
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<span id="Interleaved-and-split-arrays"></span><div class="header">
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<p>
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Next: <a href="Guru-vector-and-transform-sizes.html" accesskey="n" rel="next">Guru vector and transform sizes</a>, Previous: <a href="Guru-Interface.html" accesskey="p" rel="prev">Guru Interface</a>, Up: <a href="Guru-Interface.html" accesskey="u" rel="up">Guru Interface</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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<hr>
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<span id="Interleaved-and-split-arrays-1"></span><h4 class="subsection">4.5.1 Interleaved and split arrays</h4>
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<p>The guru interface supports two representations of complex numbers,
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which we call the interleaved and the split format.
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</p>
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<p>The <em>interleaved</em> format is the same one used by the basic and
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advanced interfaces, and it is documented in <a href="Complex-numbers.html">Complex numbers</a>.
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In the interleaved format, you provide pointers to the real part of a
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complex number, and the imaginary part understood to be stored in the
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next memory location.
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<span id="index-interleaved-format"></span>
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</p>
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<p>The <em>split</em> format allows separate pointers to the real and
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imaginary parts of a complex array.
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<span id="index-split-format"></span>
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</p>
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<p>Technically, the interleaved format is redundant, because you can
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always express an interleaved array in terms of a split array with
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appropriate pointers and strides. On the other hand, the interleaved
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format is simpler to use, and it is common in practice. Hence, FFTW
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supports it as a special case.
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</p>
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