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fftw_plan fftw_plan_r2r_1d(int n, double *in, double *out, d@0: fftw_r2r_kind kind, unsigned flags); d@0: fftw_plan fftw_plan_r2r_2d(int n0, int n1, double *in, double *out, d@0: fftw_r2r_kind kind0, fftw_r2r_kind kind1, d@0: unsigned flags); d@0: fftw_plan fftw_plan_r2r_3d(int n0, int n1, int n2, d@0: double *in, double *out, d@0: fftw_r2r_kind kind0, d@0: fftw_r2r_kind kind1, d@0: fftw_r2r_kind kind2, d@0: unsigned flags); d@0: fftw_plan fftw_plan_r2r(int rank, const int *n, double *in, double *out, d@0: const fftw_r2r_kind *kind, unsigned flags); d@0:d@0:
d@0: Plan a real input/output (r2r) transform of various kinds in zero or
d@0: more dimensions, returning an fftw_plan (see Using Plans).
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Once you have created a plan for a certain transform type and d@0: parameters, then creating another plan of the same type and parameters, d@0: but for different arrays, is fast and shares constant data with the d@0: first plan (if it still exists). d@0: d@0:
The planner returns NULL if the plan cannot be created. A
d@0: non-NULL plan is always returned by the basic interface unless
d@0: you are using a customized FFTW configuration supporting a restricted
d@0: set of transforms, or for size-1 FFTW_REDFT00 kinds (which are
d@0: not defined).
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rank is the dimensionality of the transform (it should be the
d@0: size of the arrays *n and *kind), and can be any
d@0: non-negative integer. The `_1d', `_2d', and `_3d'
d@0: planners correspond to a rank of 1, 2, and
d@0: 3, respectively. A rank of zero is equivalent to a copy
d@0: of one number from input to output.
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d@0: n, or n0/n1/n2, or n[rank],
d@0: respectively, gives the (physical) size of the transform dimensions.
d@0: They can be any positive integer.
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d@0: n0 x n1; or n0 x n1 x n2; or
d@0: n[0] x n[1] x ... x n[rank-1].
d@0: See Multi-dimensional Array Format.
d@0: performance even for prime sizes). (It is possible to customize FFTW d@0: for different array sizes; see Installation and Customization.) d@0: Transforms whose sizes are powers of 2 are especially fast. d@0:
REDFT00 or RODFT00 transform kind in a dimension of
d@0: size n, it is n-1 or n+1, respectively, that
d@0: should be factorizable in the above form.
d@0: in and out point to the input and output arrays of the
d@0: transform, which may be the same (yielding an in-place transform).
d@0: These arrays are overwritten during planning, unless
d@0: FFTW_ESTIMATE is used in the flags. (The arrays need not be
d@0: initialized, but they must be allocated.)
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d@0: kind, or kind0/kind1/kind2, or
d@0: kind[rank], is the kind of r2r transform used for the
d@0: corresponding dimension. The valid kind constants are described in
d@0: Real-to-Real Transform Kinds. In a multi-dimensional transform,
d@0: what is computed is the separable product formed by taking each
d@0: transform kind along the corresponding dimension, one dimension after
d@0: another.
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d@0: flags is a bitwise OR (`|') of zero or more planner flags,
d@0: as defined in Planner Flags.
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