kml_fft(f)_mpi_plan_r2r_3d_ext

Create a plan for the three-dimensional R2R transform of a single contiguous data array.

Interface Definition

C interface:

kml_fft_plan kml_fft_mpi_plan_r2r_3d_ext(int n0, int n1, int n2, const int *inbox_order, const int *outbox_order, const kml_fft_r2r_kind kind0, const kml_fft_r2r_kind kind1, const kml_fft_r2r_kind kind2, MPI_Comm comm, const kml_fft_mpi_options options);

kml_fftf_plan kml_fftf_mpi_plan_r2r_3d_ext(int n0, int n1, int n2, const int *inbox_order, const int *outbox_order, const kml_fftf_r2r_kind kind0, const kml_fftf_r2r_kind kind1, const kml_fftf_r2r_kind kind2, MPI_Comm comm, const kml_fftf_mpi_options options);

Return Value

The function returns a structure pointer of the kml_fft(f)_plan type. Pass the object to the kml_fft(f)_ mpi_execute_r2r_ext function as a parameter, and the input and output buffers do not need to be specified during plan creation.

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	int	Inputs the size of the first dimension in the FFT array. The constraint is n0 ≥ 1.	Input
n1	int	Inputs the size of the second dimension in the FFT array. The constraint is n1 ≥ 1.	Input
n2	int	Inputs the size of the third dimension in the FFT array. The constraint is n2 ≥ 1.	Input
inbox_order	const int *	It is a one-dimensional array with a length of 3, indicating the sequence of input data dimensions. The value is any combination of 0, 1, and 2. If this parameter is NULL, the default order is 0, 1, and 2.	Input
outbox_order	const int *	It is a one-dimensional array with a length of 3, indicating the sequence of output data dimensions. The value is any combination of 0, 1, and 2. If this parameter is NULL, the default order is 0, 1, and 2.	Input
kind0	Double precision: const kml_fft_r2r_kind Single precision: const kml_fftf_r2r_kind	kind0 indicates the R2R transform type in the first dimension of an FFT array. It has the following options: KML_FFT_R2HC KML_FFT_HC2R KML_FFT_DHT KML_FFT_REDFT00 KML_FFT_REDFT01 KML_FFT_REDFT10 KML_FFT_REDFT11 KML_FFT_RODFT00 KML_FFT_RODFT01 KML_FFT_RODFT10 KML_FFT_RODFT11	Input
kind1	Double precision: const kml_fft_r2r_kind Single precision: const kml_fftf_r2r_kind	kind1 indicates the R2R transform type in the second dimension of an FFT array. It has the following options: KML_FFT_R2HC KML_FFT_HC2R KML_FFT_DHT KML_FFT_REDFT00 KML_FFT_REDFT01 KML_FFT_REDFT10 KML_FFT_REDFT11 KML_FFT_RODFT00 KML_FFT_RODFT01 KML_FFT_RODFT10 KML_FFT_RODFT11	Input
kind2	Double precision: const kml_fft_r2r_kind Single precision: const kml_fftf_r2r_kind	kind2 indicates the R2R transform type in the third dimension of an FFT array. It has the following options: KML_FFT_R2HC KML_FFT_HC2R KML_FFT_DHT KML_FFT_REDFT00 KML_FFT_REDFT01 KML_FFT_REDFT10 KML_FFT_REDFT11 KML_FFT_RODFT00 KML_FFT_RODFT01 KML_FFT_RODFT10 KML_FFT_RODFT11	Input
comm	MPI_Comm	Communicator.	Input
options	Double precision: const kml_fft_mpi_options Single precision: const kml_fftf_mpi_options	Flag of the 3D FFT decomposition algorithm and communication algorithm.	Input

Dependencies

C: "kfft-mpi.h"

Examples

C interface:

    const int n0 = 4, n1 = 4, n2 = 4;
    kml_fft_plan plan;
    int provided;
    MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
    MPI_Comm comm = MPI_COMM_WORLD;
    double *in = NULL;
    double *out = NULL;

    /* get local data size and allocate */
    ptrdiff_t low[3] = {0};
    ptrdiff_t high[3] = {0};
    ptrdiff_t alloc_local = kml_fft_mpi_local_size_3d_ext(n0, n1, n2, comm, SCALFFT_DECOMPOSE_TYPE_PENCIL, low, high);
    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 */
    kml_fft_mpi_options options = {
        .a2a_algo    = A2A_ALGO_AUTO_TUNING,
        .decomp_type = SCALFFT_DECOMPOSE_TYPE_PENCIL
    };
    kml_fft_r2r_kind kind0 = KML_FFT_DHT;
    kml_fft_r2r_kind kind1 = KML_FFT_DHT;
    kml_fft_r2r_kind kind2 = KML_FFT_DHT;
    plan = kml_fft_mpi_plan_r2r_3d_ext(n0, n1, n2, NULL, NULL, kind0, kind1, kind2,  comm, options);    

    /* execute plan */
    int scale = 0;
    kml_fft_mpi_execute_r2r_ext(plan, in, out, scale);

    kml_fft_destroy_plan_ext(plan);

    kml_fft_free(in);
    kml_fft_free(out);
    MPI_Finalize();

Parent topic: R2R Transforms