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2 <html>
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3 <!-- This manual is for FFTW
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4 (version 3.3.5, 30 July 2016).
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5
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6 Copyright (C) 2003 Matteo Frigo.
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7
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8 Copyright (C) 2003 Massachusetts Institute of Technology.
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9
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10 Permission is granted to make and distribute verbatim copies of this
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11 manual provided the copyright notice and this permission notice are
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13
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14 Permission is granted to copy and distribute modified versions of this
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15 manual under the conditions for verbatim copying, provided that the
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16 entire resulting derived work is distributed under the terms of a
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17 permission notice identical to this one.
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18
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19 Permission is granted to copy and distribute translations of this manual
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22 approved by the Free Software Foundation. -->
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23 <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
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24 <head>
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25 <title>FFTW 3.3.5: Interleaved and split arrays</title>
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26
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27 <meta name="description" content="FFTW 3.3.5: Interleaved and split arrays">
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34 <link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
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35 <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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36 <link href="Guru-Interface.html#Guru-Interface" rel="up" title="Guru Interface">
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37 <link href="Guru-vector-and-transform-sizes.html#Guru-vector-and-transform-sizes" rel="next" title="Guru vector and transform sizes">
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65 -->
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66 </style>
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68
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69 </head>
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70
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71 <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
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72 <a name="Interleaved-and-split-arrays"></a>
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73 <div class="header">
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74 <p>
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75 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> [<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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76 </div>
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77 <hr>
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78 <a name="Interleaved-and-split-arrays-1"></a>
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79 <h4 class="subsection">4.5.1 Interleaved and split arrays</h4>
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80
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81 <p>The guru interface supports two representations of complex numbers,
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82 which we call the interleaved and the split format.
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83 </p>
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84 <p>The <em>interleaved</em> format is the same one used by the basic and
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85 advanced interfaces, and it is documented in <a href="Complex-numbers.html#Complex-numbers">Complex numbers</a>.
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86 In the interleaved format, you provide pointers to the real part of a
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87 complex number, and the imaginary part understood to be stored in the
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88 next memory location.
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89 <a name="index-interleaved-format"></a>
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90 </p>
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91
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92 <p>The <em>split</em> format allows separate pointers to the real and
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93 imaginary parts of a complex array.
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94 <a name="index-split-format"></a>
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95 </p>
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96
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97 <p>Technically, the interleaved format is redundant, because you can
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98 always express an interleaved array in terms of a split array with
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99 appropriate pointers and strides. On the other hand, the interleaved
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100 format is simpler to use, and it is common in practice. Hence, FFTW
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101 supports it as a special case.
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102 </p>
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103
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104
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105
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106 </body>
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107 </html>
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