kml_fft(f/h)_ mpi_plan_r2r_2d
Create a plan for the two-dimensional R2R transform of a single contiguous data sequence.
Interface Definition
C interface:
kml_fft_plan kml_fft_mpi_plan_r2r_2d(ptrdiff_t n0, ptrdiff_t n1, double *in, double *out, kml_fft_r2r_kind kind0, kml_fft_r2r_kind kind1, MPI_Comm comm, unsigned flags);
kml_fftf_plan kml_fftf_mpi_plan_r2r_2d(ptrdiff_t n0, ptrdiff_t n1, float *in, float *out, kml_fftf_r2r_kind kind0, kml_fftf_r2r_kind kind1, MPI_Comm comm, unsigned flags);
kml_ffth_plan kml_ffth_mpi_plan_r2r_2d(ptrdiff_t n0, ptrdiff_t n1, __fp16 *in, __fp16 *out, kml_ffth_r2r_kind kind0, kml_ffth_r2r_kind kind1, MPI_Comm comm, unsigned flags);
Return Value
The function returns a structure pointer of the kml_fft(f)_plan type. This object can be passed to the kml_fft(f)_execute function as a parameter to perform FFT on the current input and output. It can also be passed to the kml_fft(f)_execute_r2r function as a parameter to perform FFT on new input and output.
If this function returns a non-null pointer, the plan has been successfully created. Otherwise, the plan fails to be created.
Parameters
Parameter |
Data Type |
Description |
Input/Output |
|---|---|---|---|
n0 |
ptrdiff_t |
Inputs the size of the first dimension in the FFT sequence. The constraint is n0 ≥ 1. |
Input |
n1 |
ptrdiff_t |
Inputs the size of the second dimension in the FFT sequence. The constraint is n1 ≥ 1. |
Input |
in |
|
Inputs the data to be transformed. |
Input |
out |
|
Outputs the data generated using FFT. |
Output |
kind0 |
|
kind0 indicates the R2R transform type in the first dimension of an FFT sequence. It has the following options:
|
Input |
kind1 |
|
kind1 indicates the R2R transform type in the second dimension of an FFT sequence. It has the following options:
|
Input |
comm |
MPI_Comm |
MPI communicator handle. |
Input |
flags |
unsigned int |
Planning option, which can be set to: KML_FFT_ESTIMATE: ESTIMATE mode KML_FFT_PATIENT: PATIENT mode KML_FFT_MPI_SCRAMBLED_[IN|OUT]: The input/output is in scrambled format. This option takes effect only for one-dimensional transform. KML_FFT_MPI_TRANSPOSED_[IN|OUT]: The input/output is transposed from n0 × n1 × n2 ×... × nd-1 to n1 × n0 × n2 ×…× nd-1. |
Input |
Dependencies
C: "kfft-mpi.h"
Examples
C interface:
const ptrdiff_t N0 = 4, N1 = 4;
kml_fft_plan plan;
ptrdiff_t alloc_local, local_n0, local_0_start;
MPI_Init(&argc, &argv);
MPI_Comm comm = MPI_COMM_WORLD;
kml_fft_mpi_init();
kml_fft_r2r_kind kind0 = KML_FFT_R2HC;
kml_fft_r2r_kind kind1 = KML_FFT_R2HC;
double *in = NULL;
double *out = NULL;
/* get local data size and allocate */
alloc_local = kml_fft_mpi_local_size_2d(N0, N1, comm, &local_n0, &local_0_start);
if (alloc_local == -1) {
printf("[%s][%d] allocate size fail.\n", __func__, __LINE__);
}
in = (double *)kml_fft_malloc(sizeof(double) * alloc_local);
if (in == NULL) {
printf("[%s][%d] malloc memory fail.\n", __func__, __LINE__);
}
out = (double *)kml_fft_malloc(sizeof(double) * alloc_local);
if (out == NULL) {
printf("[%s][%d] malloc memory fail.\n", __func__, __LINE__);
}
/* create plan for in-place forward DFT */
plan = kml_fft_mpi_plan_r2r_2d(N0, N1, in, out, comm, kind0, kind1, KML_FFT_MPI_TRANSPOSED_IN);
/* compute transforms, in-place, as many times as desired */
kml_fft_execute_r2r(plan, in, out);
kml_fft_destroy_plan(plan);
kml_fft_mpi_cleanup();
MPI_Finalize();