建立多组数据序列n维R2R变换的plan。其中,单个FFT的数据序列不需要是连续的,可以以跨步的形式提供。
C interface:
kml_fft_plan kml_fft_plan_guru_r2r(int rank, const kml_fft_iodim *dims, int howmany_rank, const kml_fft_iodim *howmany_dims, double *in, double *out, const kml_fft_r2r_kind *kind, unsigned flags);
kml_fftf_plan kml_fftf_plan_guru_r2r(int rank, const kml_fftf_iodim *dims, int howmany_rank, const kml_fftf_iodim *howmany_dims, float *in, float *out, const kml_fftf_r2r_kind *kind, unsigned flags);
kml_ffth_plan kml_ffth_plan_guru_r2r(int rank, const kml_ffth_iodim *dims, int howmany_rank, const kml_ffth_iodim *howmany_dims, float *in, __fp16 *out, const kml_ffth_r2r_kind *kind, unsigned flags);
Fortran interface:
RES = KML_FFT_PLAN_GURU_DFT_R2R(RANK, DIMS, HOWMANY_RANK, HOWMANY_DIMS, IN, OUT, KIND, FLAGS);
RES = KML_FFTF_PLAN_GURU_DFT_R2R(RANK, DIMS, HOWMANY_RANK, HOWMANY_DIMS, IN, OUT, KIND, FLAGS);
RES = KML_FFTH_PLAN_GURU_DFT_R2R(RANK, DIMS, HOWMANY_RANK, HOWMANY_DIMS, IN, OUT, KIND, FLAGS);
KML_FFT_REDFT11和KML_FFT_ROODFT11只支持长度为4的整数倍大小的序列,其他变换类型只支持长度为2的整数倍大小的序列。
函数返回一个kml_fft(f/h)_plan类型的结构体指针。将该对象作为参数传入kml_fft(f/h)_execute函数中使用,将对当前提供的输入in和输出out执行FFT变换;另外,也可以通过将该对象作为参数传入kml_fft(f/h)_execute_r2r函数中以对新的输入in和输出out执行FFT变换。
如果函数返回非空指针,则表示plan执行成功,否则表示执行失败。
参数名 |
数据类型 |
描述 |
输入/输出 |
---|---|---|---|
rank |
int |
单个FFT序列的维度。 约束:1 ≤ rank ≤ 3。 |
输入 |
dims |
|
dims是大小为rank的结构体数组,dims[i]包含以下成员:
约束:dims[i].n ≥ 1, for i in 0 to rank - 1。 |
输入 |
howmany_rank |
int |
多个rank维FFT之间的内存排布用howmany_rank维的howmany_dims数组来描述,howmany_rank表示每个要计算的rank维FFT变换的起始地址的内存访问模式所需的维数。 约束:0 ≤ howmany_rank ≤ 3。 |
输入 |
howmany_dims |
|
howmany_dims是大小为howmany_rank的结构体数组,howmany_dims[i]包含以下成员:
|
输入 |
in |
|
输入待变换的数据。 |
输入 |
out |
|
输出快速傅里叶变换后的数据。 |
输出 |
kind |
|
kind是大小为rank的数组,包含FFT序列每一维度的R2R变换类型,kind[i] (for i in 0 to rank - 1)有以下可选值:
|
输入 |
flags |
unsigned int |
planning选项,描述ESTIMATE模式或PATIENT模式。 KML_FFT_ESTIMATE:ESTIMATE模式 KML_FFT_PATIENT:PATIENT模式 |
输入 |
C: "kfft.h"
C interface:
int rank = 2; kml_fft_iodim *dims; dims = (kml_fft_iodim*)kml_fft_malloc(sizeof(kml_fft_iodim) * rank); dims[0].n = 2; dims[0].is = 2; dims[0].os = 2; dims[1].n = 2; dims[1].is = 1; dims[1].os = 1; int howmany_rank = 1; kml_fft_iodim *howmany_dims; howmany_dims = (kml_fft_iodim*)kml_fft_malloc(sizeof(kml_fft_iodim) * howmany_rank); howmany_dims[0].n = 2; howmany_dims[0].is = 2 * 2; howmany_dims[0].os = 2 * 2; double init[8] = {120, 0, 8, 8, 0, 0, 0, 16}; double *in; in = (double*)kml_fft_malloc(sizeof(double) * 8); for (int i = 0; i < 8; i++) { in[i] = init[i]; } double *out; out = (double*)kml_fft_malloc(sizeof(double) * 8); kml_fft_r2r_kind *kind; kind = (kml_fft_r2r_kind*)kml_fft_malloc(sizeof(kml_fft_r2r_kind) * rank); kind[0] = KML_FFT_DHT; kind[1] = KML_FFT_REDFT01; kml_fft_plan plan; plan = kml_fft_plan_guru_r2r(rank, dims, howmany_rank, howmany_dims, in, out, kind, KML_FFT_ESTIMATE); kml_fft_execute_r2r(plan, in, out); kml_fft_destroy_plan(plan); kml_fft_free(howmany_dims); kml_fft_free(dims); kml_fft_free(kind); kml_fft_free(in); kml_fft_free(out); /* * out = {1.393137e+02, 1.166863e+02, 1.006863e+02, 1.233137e+02, * 2.262742e+01, -2.262742e+01, -2.262742e+01, 2.262742e+01} */
Fortran interface:
INTEGER(C_INT) :: RANK = 2 INTEGER(C_INT) :: KIND(2) INTEGER(C_INT) :: HOWMANY_RANK = 1 TYPE(KML_FFT_IODIM), POINTER :: DIMS(:), HOWMANY_DIMS(:) REAL(C_DOUBLE), DIMENSION(8) :: INIT TYPE(C_DOUBLE), POINTER :: IN(:), OUT(:) TYPE(C_PTR) :: PIN, POUT, PDIMS, PHOWMANY_DIMS INTEGER(C_SIZE_T) :: SIZE1, SIZE2, SIZE3 SIZE1 = 8 * 12 SIZE3 = 12 * RANK SIZE4 = 12 * HOWMANY_RANK PDIMS = KML_FFT_MALLOC(SIZE2) PHOWMANY_DIMS = KML_FFT_MALLOC(SIZE3) PIN = KML_FFT_MALLOC(SIZE1) POUT = KML_FFT_MALLOC(SIZE1) CALL C_F_POINTER(PIN, IN, SHAPE=[8]) CALL C_F_POINTER(POUT, OUT, SHAPE=[8]) CALL C_F_POINTER(PDIMS, DIMS, SHAPE=[RANK]) CALL C_F_POINTER(PHOWMANY_DIMS, HOWMANY_DIMS, SHAPE=[HOWMANY_RANK]) DIMS(0)%N = 2 DIMS(0)%IS = 2 DIMS(0)%OS = 2 DIMS(1)%N = 2 DIMS(1)%IS = 1 DIMS(1)%OS = 1 HOWMANY_DIMS(0)%N = 2 HOWMANY_DIMS(0)%IS = 2 * 2 HOWMANY_DIMS(0)%OS = 2 * 2 DATA INIT/120, 0, 8, 8, 0, 0, 0, 16/ INTEGER :: I DO WHILE(I <= 8) IN(I) = INIT(I) END DO KIND(0) = KML_FFT_DHT KIND(1) = KML_FFT_REDFT01 TYPE(C_PTR) :: PLAN PLAN = KML_FFT_PLAN_GURU_R2R(RANK, DIMS, HOWMANY_RANK, HOWMANY_DIMS, IN, OUT, KIND, KML_FFT_ESTIMATE) CALL KML_FFT_EXECUTE_R2R(PLAN, IN, OUT) CALL KML_FFT_DESTROY_PLAN(PLAN) CALL KML_FFT_FREE(PHOWMANY_DIMS) CALL KML_FFT_FREE(PDIMS) CALL KML_FFT_FREE(PIN) CALL KML_FFT_FREE(POUT) ! ! OUT = /1.393137E+02, 1.166863E+02, 1.006863E+02, 1.233137E+02, ! 2.262742E+01, -2.262742E+01, -2.262742E+01, 2.262742E+01/ !