cannam@167: Next: Real-to-Real Transform Kinds, Previous: Real-data DFT Array Format, Up: Basic Interface [Contents][Index]
cannam@167:fftw_plan fftw_plan_r2r_1d(int n, double *in, double *out, cannam@167: fftw_r2r_kind kind, unsigned flags); cannam@167: fftw_plan fftw_plan_r2r_2d(int n0, int n1, double *in, double *out, cannam@167: fftw_r2r_kind kind0, fftw_r2r_kind kind1, cannam@167: unsigned flags); cannam@167: fftw_plan fftw_plan_r2r_3d(int n0, int n1, int n2, cannam@167: double *in, double *out, cannam@167: fftw_r2r_kind kind0, cannam@167: fftw_r2r_kind kind1, cannam@167: fftw_r2r_kind kind2, cannam@167: unsigned flags); cannam@167: fftw_plan fftw_plan_r2r(int rank, const int *n, double *in, double *out, cannam@167: const fftw_r2r_kind *kind, unsigned flags); cannam@167:
Plan a real input/output (r2r) transform of various kinds in zero or
cannam@167: more dimensions, returning an fftw_plan (see Using Plans).
cannam@167:
Once you have created a plan for a certain transform type and cannam@167: parameters, then creating another plan of the same type and parameters, cannam@167: but for different arrays, is fast and shares constant data with the cannam@167: first plan (if it still exists). cannam@167:
cannam@167:The planner returns NULL if the plan cannot be created. A
cannam@167: non-NULL plan is always returned by the basic interface unless
cannam@167: you are using a customized FFTW configuration supporting a restricted
cannam@167: set of transforms, or for size-1 FFTW_REDFT00 kinds (which are
cannam@167: not defined).
cannam@167:
cannam@167:
rank is the dimensionality of the transform (it should be the
cannam@167: size of the arrays *n and *kind), and can be any
cannam@167: non-negative integer. The ‘_1d’, ‘_2d’, and ‘_3d’
cannam@167: planners correspond to a rank of 1, 2, and
cannam@167: 3, respectively. A rank of zero is equivalent to a copy
cannam@167: of one number from input to output.
cannam@167:
cannam@167: n, or n0/n1/n2, or n[rank],
cannam@167: respectively, gives the (physical) size of the transform dimensions.
cannam@167: They can be any positive integer.
cannam@167:
cannam@167: n0 x n1; or n0 x n1 x n2; or
cannam@167: n[0] x n[1] x ... x n[rank-1].
cannam@167: See Multi-dimensional Array Format.
cannam@167: REDFT00 or RODFT00 transform kind in a dimension of
cannam@167: size n, it is n-1 or n+1, respectively, that
cannam@167: should be factorizable in the above form.
cannam@167: in and out point to the input and output arrays of the
cannam@167: transform, which may be the same (yielding an in-place transform).
cannam@167:
cannam@167: These arrays are overwritten during planning, unless
cannam@167: FFTW_ESTIMATE is used in the flags. (The arrays need not be
cannam@167: initialized, but they must be allocated.)
cannam@167:
cannam@167: kind, or kind0/kind1/kind2, or
cannam@167: kind[rank], is the kind of r2r transform used for the
cannam@167: corresponding dimension. The valid kind constants are described in
cannam@167: Real-to-Real Transform Kinds. In a multi-dimensional transform,
cannam@167: what is computed is the separable product formed by taking each
cannam@167: transform kind along the corresponding dimension, one dimension after
cannam@167: another.
cannam@167:
cannam@167: flags is a bitwise OR (‘|’) of zero or more planner flags,
cannam@167: as defined in Planner Flags.
cannam@167:
cannam@167: cannam@167: Next: Real-to-Real Transform Kinds, Previous: Real-data DFT Array Format, Up: Basic Interface [Contents][Index]
cannam@167: