kml_ffth_plan_many_dft_scale_r2c

Create a plan for the n-dimensional R2C transform of howmany data sequences. The data sequence of a single FFT does not need to be contiguous and can be strided.

Interface Definition

C interface:

kml_ffth_plan kml_ffth_plan_many_dft_scale_r2c(int rank, const int *n, int howmany, __fp16 *in, const int *inembed, int istride, int idist, kml_ffth_float_complex *out, const int *onembed, int ostride, int odist, unsigned flags);

Return Value

The function returns a structure pointer of the kml_ffth_plan type. This object can be passed to the kml_fft(f/h)_execute function as a parameter to perform FFT on the current input and output. This object can also be passed to the kml_ffth_execute_dft_scale_r2c 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
rank	int	Dimension of FFT. The constraint is 1 ≤ rank ≤ 4.	Input
n	const int*	Indicates an array whose dimension is rank, including the size of each dimension in the FFT sequence. The constraint is n[i] ≥ 1, for i in 0 to rank - 1.	Input
howmany	int	Indicates how many multi-dimensional FFTs are needed.	Input
in	__fp16*	Inputs the data to be transformed.	Input
inembed	const int*	An array whose size is rank or NULL. This array indicates the size of each dimension of a larger space for input FFT data storage. Constraint: inembed[i] ≥ n[i] for i in 0, rank-1. Or if inembed == NULL, inembed is equal to n.	Input
istride	int	Interval between successive elements of the i-th dimensional FFT input sequence.	Input
idist	int	idist indicates the interval between FFT input sequences.	Input
out	kml_ffth_float_complex*	Outputs the data generated using FFT.	Output
onembed	const int*	onembed is an array whose size is rank or NULL. This array indicates the size of each dimension of a larger space for output FFT data storage. Constraint: onembed[i] ≥ n[i] for i in 0, rank-1. Or if onembed == NULL, onembed is equal to n.	Input
ostride	int	Interval between successive elements of the i-th dimensional FFT output sequence.	Input
odist	int	odist indicates the interval between FFT output sequences.	Input
flags	unsigned int	Planning option, which describes the ESTIMATE or PATIENT mode. KML_FFT_ESTIMATE: ESTIMATE mode KML_FFT_PATIENT: PATIENT mode	Input

Dependencies

C: "kfft.h"

Examples

C interface:

    int rank = 1; 
    int *n; 
    n = (int*)kml_ffth_malloc(sizeof(int) * rank); 
    n[0] = 4; 
    int howmany = 3; 
    int istride = 1; 
    int ostride = 1; 
    int idist = 4; 
    int odist = n[0] / 2 + 1; 
    __fp16 init[12] = {120, 8, 0, 0, 0, -8, -8, -8, -16, 0, -40, -8}; 
    __fp16 *in; 
    in = (__fp16*)kml_ffth_malloc(sizeof(__fp16) * 12); 
    for (int i = 0; i < 12; i++) { 
        in[i] = init[i]; 
    } 
    kml_ffth_float_complex *out; 
    out = (kml_ffth_float_complex*)kml_ffth_malloc(sizeof(kml_ffth_float_complex) * (n[0] / 2 + 1) * howmany); 
    kml_ffth_plan plan; 
    plan = kml_ffth_plan_many_dft_scale_r2c(rank, n, howmany, in, NULL, istride, idist, out, NULL, ostride, odist, KML_FFT_ESTIMATE); 
    kml_ffth_execute_dft_scale_r2c(plan, in, out); 
 
    kml_ffth_destroy_plan(plan); 
    kml_ffth_free(n); 
    kml_ffth_free(in); 
    kml_ffth_free(out); 
 
    /* 
     * out = {{1.280000e+02, 0.000000e+00}, {1.200000e+02, -8.000000e+00}, 
     *        {1.120000e+02, 0.000000e+00}, {-2.400000e+01, 0.000000e+00}, 
     *        {8.000000e+00, -0.000000e+00}, {8.000000e+00, 0.000000e+00}, 
     *        {-6.400000e+01, 0.000000e+00}, {2.400000e+01, -8.000000e+00}, 
     *        {-4.800000e+01, 0.000000e+00}} 
     */

Parent topic: R2C Transforms