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fftw_plan fftw_plan_guru_dft_r2c( Chris@19: int rank, const fftw_iodim *dims, Chris@19: int howmany_rank, const fftw_iodim *howmany_dims, Chris@19: double *in, fftw_complex *out, Chris@19: unsigned flags); Chris@19: Chris@19: fftw_plan fftw_plan_guru_split_dft_r2c( Chris@19: int rank, const fftw_iodim *dims, Chris@19: int howmany_rank, const fftw_iodim *howmany_dims, Chris@19: double *in, double *ro, double *io, Chris@19: unsigned flags); Chris@19: Chris@19: fftw_plan fftw_plan_guru_dft_c2r( Chris@19: int rank, const fftw_iodim *dims, Chris@19: int howmany_rank, const fftw_iodim *howmany_dims, Chris@19: fftw_complex *in, double *out, Chris@19: unsigned flags); Chris@19: Chris@19: fftw_plan fftw_plan_guru_split_dft_c2r( Chris@19: int rank, const fftw_iodim *dims, Chris@19: int howmany_rank, const fftw_iodim *howmany_dims, Chris@19: double *ri, double *ii, double *out, Chris@19: unsigned flags); Chris@19:Chris@19:
Chris@19: Plan a real-input (r2c) or real-output (c2r), multi-dimensional DFT with
Chris@19: transform dimensions given by (rank, dims) over a
Chris@19: multi-dimensional vector (loop) of dimensions (howmany_rank,
Chris@19: howmany_dims). dims and howmany_dims should point
Chris@19: to fftw_iodim arrays of length rank and
Chris@19: howmany_rank, respectively. As for the basic and advanced
Chris@19: interfaces, an r2c transform is FFTW_FORWARD and a c2r transform
Chris@19: is FFTW_BACKWARD.
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The last dimension of dims is interpreted specially:
Chris@19: that dimension of the real array has size dims[rank-1].n, but
Chris@19: that dimension of the complex array has size dims[rank-1].n/2+1
Chris@19: (division rounded down). The strides, on the other hand, are taken to
Chris@19: be exactly as specified. It is up to the user to specify the strides
Chris@19: appropriately for the peculiar dimensions of the data, and we do not
Chris@19: guarantee that the planner will succeed (return non-NULL) for
Chris@19: any dimensions other than those described in Real-data DFT Array Format and generalized in Advanced Real-data DFTs. (That is,
Chris@19: for an in-place transform, each individual dimension should be able to
Chris@19: operate in place.)
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in and out point to the input and output arrays for r2c
Chris@19: and c2r transforms, respectively. For split arrays, ri and
Chris@19: ii point to the real and imaginary input arrays for a c2r
Chris@19: transform, and ro and io point to the real and imaginary
Chris@19: output arrays for an r2c transform. in and ro or
Chris@19: ri and out may be the same, indicating an in-place
Chris@19: transform. (In-place transforms where in and io or
Chris@19: ii and out are the same are not currently supported.)
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flags is a bitwise OR (‘|’) of zero or more planner flags,
Chris@19: as defined in Planner Flags.
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In-place transforms of rank greater than 1 are currently only
Chris@19: supported for interleaved arrays. For split arrays, the planner will
Chris@19: return NULL.
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