kml_fft(f)_plan_dft_3d
Create a plan for the three-dimensional C2C transform of a single contiguous data sequence.
Interface Definition
C interface:
kml_fft_plan kml_fft_plan_dft_3d(int n0, int n1, int n2, kml_fft_complex *in, kml_fft_complex *out, int sign, unsigned flags);
kml_fftf_plan kml_fftf_plan_dft_3d(int n0, int n1, int n2, kml_fftf_complex *in, kml_fftf_complex *out, int sign, unsigned flags);
Fortran interface:
RES = KML_FFT_PLAN_DFT_3D(N0, N1, N2, IN, OUT, SIGN, FLAGS);
RES = KML_FFTF_PLAN_DFT_3D(N0, N1, N2, IN, OUT, SIGN, FLAGS);
Return Value
The function returns a structure pointer of the kml_fft(f)_plan type. This object is used as a parameter in the kml_fft(f)_execute function to perform FFT on the current input and output. In addition, the object may also be added into the kml_fft(f)_execute_dft function as a parameter to perform FFT on the new input and output.
If this function returns a non-null pointer, the plan has been successfully executed. Otherwise, the plan failed to be executed.
Parameters
Parameter |
Data Type |
Description |
Input/Output |
|---|---|---|---|
n0 |
int |
Inputs the size of the first dimension in the FFT sequence. The constraint is n0 ≥ 1. |
Input |
n1 |
int |
Inputs the size of the second dimension in the FFT sequence. The constraint is n1 ≥ 1. |
Input |
n2 |
int |
Inputs the size of the third dimension in the FFT sequence. The constraint is n2≥ 1. |
Input |
in |
|
Inputs the data to be transformed. |
Input |
out |
|
Outputs the data generated using FFT. |
Output |
sign |
int |
Specifies forward or backward transform.
|
Input |
flags |
unsigned int |
A planning option, not in use. |
Input |
Dependencies
C: "kfft.h"
Fortran: "kfft.f03"
Examples
C interface:
int n0 = 2;
int n1 = 3;
int n2 = 2;
double init[12][2] = {{120, 0}, {8, 8}, {0, 0}, {0, 16}, {0, 16}, {-8, 8}, {-8, 0}, {-8, 8}, {-16, 0}, {0, -16}, {-40, 8}, {-8, -8}};
kml_fft_complex *in;
in = (kml_fft_complex*)kml_fft_malloc(sizeof(kml_fft_complex) * n0 * n1 * n2);
for (int i = 0; i < n0 * n1 * n2; i++) {
in[i].r = init[i][0];
in[i].i = init[i][1];
}
kml_fft_complex *out;
out = (kml_fft_complex*)kml_fft_malloc(sizeof(kml_fft_complex) * n0 * n1 * n2);
kml_fft_plan plan;
plan = kml_fft_plan_dft_3d(n0, n1, n2, in, out, KML_FFT_FORWARD, KML_FFT_ESTIMATE);
kml_fft_execute_dft(plan, in, out);
kml_fft_destroy_plan(plan);
kml_fft_free(in);
kml_fft_free(out);
/*
* out = {{4.000000e+01, 4.000000e+01}, {7.200000e+01, 8.000000e+00},
* {1.272154e+02, -3.064102e+01}, {1.112154e+02, -3.492820e+01},
* {1.687846e+02, 3.864102e+01}, {1.527846e+02, -2.107180e+01},
* {2.000000e+02, 5.600000e+01}, {1.680000e+02, -4.000000e+01},
* {1.229282e+02, -7.215390e+00}, {6.321539e+01, 4.078461e+01},
* {1.090718e+02, -4.878461e+01}, {1.047846e+02, -7.846097e-01}}
*/
Fortran interface:
INTEGER(C_INT) :: N0 = 2
INTEGER(C_INT) :: N1 = 3
INTEGER(C_INT) :: N2 = 2
REAL(C_DOUBLE), DIMENSION(12, 2) :: INIT
TYPE(KML_FFT_COMPLEX), POINTER :: IN(:), OUT(:)
TYPE(C_PTR) :: PIN, POUT
TYPE(C_SIZE_T) :: SIZE
SIZE = 16 * N0 * N1 * N2
PIN = KML_FFT_MALLOC(SIZE)
POUT = KML_FFT_MALLOC(SIZE)
CALL C_F_POINTER(PIN, IN, SHAPE=[N0 * N1 * N2])
CALL C_F_POINTER(POUT, OUT, SHAPE=[N0 * N1 * N2])
DATA INIT/120, 8, 0, 0, 0, -8, -8, -8, -16, 0, -40, -8, 0, 8, 0, 16, 16, 8, 0, 8, 0, -16, 8, -8/
INTEGER :: I
DO WHILE(I <= N0 * N1 * N2)
IN%R = INIT(I, 0)
IN%I = INIT(I, 1)
END DO
TYPE(C_PTR) :: PLAN
PLAN = KML_FFT_PLAN_DFT_3D(N0, N1, N2, IN, OUT, KML_FFT_FORWARD, KML_FFT_ESTIMATE)
CALL KML_FFT_EXECUTE_DFT(PLAN, IN, OUT)
CALL KML_FFT_DESTROY_PLAN(PLAN)
CALL KML_FFT_FREE(PIN)
CALL KML_FFT_FREE(POUT)
!
! OUT = /4.000000E+01, 4.000000E+01, 7.200000E+01, 8.000000E+00,
! 1.272154E+02, -3.064102E+01, 1.112154E+02, -3.492820E+01,
! 1.687846E+02, 3.864102E+01, 1.527846E+02, -2.107180E+01,
! 2.000000E+02, 5.600000E+01, 1.680000E+02, -4.000000E+01,
! 1.229282E+02, -7.215390E+00, 6.321539E+01, 4.078461E+01,
! 1.090718E+02, -4.878461E+01, 1.047846E+02, -7.846097E-01/
!