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3 <title>Interleaved and split arrays - FFTW 3.3.3</title>
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12 <!--
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13 This manual is for FFTW
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14 (version 3.3.3, 25 November 2012).
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15
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16 Copyright (C) 2003 Matteo Frigo.
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17
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18 Copyright (C) 2003 Massachusetts Institute of Technology.
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24 Permission is granted to copy and distribute modified versions of
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25 this manual under the conditions for verbatim copying, provided
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26 that the entire resulting derived work is distributed under the
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47 <body>
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48 <div class="node">
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49 <a name="Interleaved-and-split-arrays"></a>
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50 <p>
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51 Next: <a rel="next" accesskey="n" href="Guru-vector-and-transform-sizes.html#Guru-vector-and-transform-sizes">Guru vector and transform sizes</a>,
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52 Previous: <a rel="previous" accesskey="p" href="Guru-Interface.html#Guru-Interface">Guru Interface</a>,
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53 Up: <a rel="up" accesskey="u" href="Guru-Interface.html#Guru-Interface">Guru Interface</a>
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54 <hr>
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55 </div>
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56
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57 <h4 class="subsection">4.5.1 Interleaved and split arrays</h4>
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58
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59 <p>The guru interface supports two representations of complex numbers,
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60 which we call the interleaved and the split format.
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61
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62 <p>The <dfn>interleaved</dfn> format is the same one used by the basic and
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63 advanced interfaces, and it is documented in <a href="Complex-numbers.html#Complex-numbers">Complex numbers</a>.
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64 In the interleaved format, you provide pointers to the real part of a
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65 complex number, and the imaginary part understood to be stored in the
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66 next memory location.
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67 <a name="index-interleaved-format-241"></a>
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68
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69 <p>The <dfn>split</dfn> format allows separate pointers to the real and
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70 imaginary parts of a complex array.
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71 <a name="index-split-format-242"></a>
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72
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73 <p>Technically, the interleaved format is redundant, because you can
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74 always express an interleaved array in terms of a split array with
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75 appropriate pointers and strides. On the other hand, the interleaved
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76 format is simpler to use, and it is common in practice. Hence, FFTW
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77 supports it as a special case.
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78
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79 <!-- =========> -->
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80 </body></html>
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81
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