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Next: <a href="Guru-vector-and-transform-sizes.html#Guru-vector-and-transform-sizes" accesskey="n" rel="next">Guru vector and transform sizes</a>, Previous: <a href="Guru-Interface.html#Guru-Interface" accesskey="p" rel="prev">Guru Interface</a>, Up: <a href="Guru-Interface.html#Guru-Interface" accesskey="u" rel="up">Guru Interface</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Interleaved-and-split-arrays-1"></a>
<h4 class="subsection">4.5.1 Interleaved and split arrays</h4>

<p>The guru interface supports two representations of complex numbers,
which we call the interleaved and the split format.
</p>
<p>The <em>interleaved</em> format is the same one used by the basic and
advanced interfaces, and it is documented in <a href="Complex-numbers.html#Complex-numbers">Complex numbers</a>.
In the interleaved format, you provide pointers to the real part of a
complex number, and the imaginary part understood to be stored in the
next memory location.
<a name="index-interleaved-format"></a>
</p>

<p>The <em>split</em> format allows separate pointers to the real and
imaginary parts of a complex array.
<a name="index-split-format"></a>
</p>

<p>Technically, the interleaved format is redundant, because you can
always express an interleaved array in terms of a split array with
appropriate pointers and strides.  On the other hand, the interleaved
format is simpler to use, and it is common in practice.  Hence, FFTW
supports it as a special case.
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author	Chris Cannam <cannam@all-day-breakfast.com>
date	Mon, 02 Mar 2020 14:03:47 +0000
parents	7867fa7e1b6b
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