int main(int argc, char **argv){
int np[2];
ptrdiff_t n[3], ni[3], no[3], N[3];
ptrdiff_t alloc_local_forw, alloc_local_back, alloc_local, howmany;
ptrdiff_t local_ni[3], local_i_start[3];
ptrdiff_t local_n[3], local_start[3];
ptrdiff_t local_no[3], local_o_start[3];
double err, *in, *out;
pfft_plan plan_forw=NULL, plan_back=NULL;
MPI_Comm comm_cart_2d;
fftw_r2r_kind kinds_forw[3], kinds_back[3];
/* Set size of FFT and process mesh */
ni[0] = ni[1] = ni[2] = 16;
n[0] = 29; n[1] = 27; n[2] = 31;
for(int t=0; t<3; t++)
no[t] = ni[t];
np[0] = 2; np[1] = 2;
howmany = 1;
/* Set PFFT kinds of 1d R2R trafos */
kinds_forw[0] = PFFT_REDFT00; kinds_back[0] = PFFT_REDFT00;
kinds_forw[1] = PFFT_REDFT01; kinds_back[1] = PFFT_REDFT10;
kinds_forw[2] = PFFT_RODFT00; kinds_back[2] = PFFT_RODFT00;
/* Set logical DFT sizes corresponding to FFTW manual:
* for REDFT00 N=2*(n-1), for RODFT00 N=2*(n+1), otherwise N=2*n */
N[0] = 2*(n[0]-1);
N[1] = 2*n[1];
N[2] = 2*(n[2]+1);
/* Initialize MPI and PFFT */
MPI_Init(&argc, &argv);
pfft_init();
/* Create two-dimensional process grid of size np[0] x np[1], if possible */
if( pfft_create_procmesh_2d(MPI_COMM_WORLD, np[0], np[1], &comm_cart_2d) ){
pfft_fprintf(MPI_COMM_WORLD, stderr, "Error: This test file only works with %d processes.\n", np[0]*np[1]);
MPI_Finalize();
return 1;
}
/* Get parameters of data distribution */
alloc_local_forw = pfft_local_size_many_r2r(3, n, ni, n, howmany,
PFFT_DEFAULT_BLOCKS, PFFT_DEFAULT_BLOCKS,
comm_cart_2d, PFFT_TRANSPOSED_OUT,
local_ni, local_i_start, local_n, local_start);
alloc_local_back = pfft_local_size_many_r2r(3, n, n, no, howmany,
PFFT_DEFAULT_BLOCKS, PFFT_DEFAULT_BLOCKS,
comm_cart_2d, PFFT_TRANSPOSED_IN,
local_n, local_start, local_no, local_o_start);
/* Allocate enough memory for both trafos */
alloc_local = (alloc_local_forw > alloc_local_back) ?
alloc_local_forw : alloc_local_back;
in = fftw_alloc_real(alloc_local);
out = fftw_alloc_real(alloc_local);
/* Plan parallel forward FFT */
plan_forw = pfft_plan_many_r2r(
3, n, ni, n, howmany, PFFT_DEFAULT_BLOCKS, PFFT_DEFAULT_BLOCKS,
in, out, comm_cart_2d, kinds_forw, PFFT_TRANSPOSED_OUT| PFFT_MEASURE| PFFT_DESTROY_INPUT);
/* Plan parallel backward FFT */
plan_back = pfft_plan_many_r2r(
3, n, n, no, howmany, PFFT_DEFAULT_BLOCKS, PFFT_DEFAULT_BLOCKS,
out, in, comm_cart_2d, kinds_back, PFFT_TRANSPOSED_IN| PFFT_MEASURE| PFFT_DESTROY_INPUT);
/* Initialize input with random numbers */
pfft_init_input_real_3d(ni, local_ni, local_i_start,
in);
/* Execute parallel forward FFT */
pfft_execute(plan_forw);
/* clear the old input */
pfft_clear_input_real_3d(ni, local_ni, local_i_start,
in);
/* execute parallel backward FFT */
pfft_execute(plan_back);
/* Scale data */
for(ptrdiff_t l=0; l < local_ni[0] * local_ni[1] * local_ni[2]; l++)
in[l] /= (N[0]*N[1]*N[2]);
/* Print error of back transformed data */
MPI_Barrier(MPI_COMM_WORLD);
err = pfft_check_output_real_3d(ni, local_ni, local_i_start, in, comm_cart_2d);
pfft_printf(comm_cart_2d, "Error after one forward and backward trafo of size n=(%td, %td, %td):\n", n[0], n[1], n[2]);
pfft_printf(comm_cart_2d, "maxerror = %6.2e;\n", err);
/* free mem and finalize MPI */
pfft_destroy_plan(plan_forw);
pfft_destroy_plan(plan_back);
MPI_Comm_free(&comm_cart_2d);
fftw_free(in); fftw_free(out);
MPI_Finalize();
return 0;
}
int main(int argc, char **argv)
{
int np[2];
ptrdiff_t n[3], N[3];
ptrdiff_t alloc_local;
ptrdiff_t local_ni[3], local_i_start[3];
ptrdiff_t local_no[3], local_o_start[3];
double err, *in, *out;
pfft_plan plan_forw=NULL, plan_back=NULL;
MPI_Comm comm_cart_2d;
pfft_r2r_kind kinds_forw[3], kinds_back[3];
/* Set size of FFT and process mesh */
n[0] = 29; n[1] = 27; n[2] = 31;
np[0] = 2; np[1] = 2;
/* Set FFTW kinds of 1d R2R trafos */
kinds_forw[0] = PFFT_REDFT00; kinds_back[0] = PFFT_REDFT00;
kinds_forw[1] = PFFT_REDFT01; kinds_back[1] = PFFT_REDFT10;
kinds_forw[2] = PFFT_RODFT00; kinds_back[2] = PFFT_RODFT00;
/* Set logical DFT sizes corresponding to FFTW manual:
* for REDFT00 N=2*(n-1), for RODFT00 N=2*(n+1), otherwise N=2*n */
N[0] = 2*(n[0]-1);
N[1] = 2*n[1];
N[2] = 2*(n[2]+1);
/* Initialize MPI and PFFT */
MPI_Init(&argc, &argv);
pfft_init();
/* Create two-dimensional process grid of size np[0] x np[1], if possible */
if( pfft_create_procmesh_2d(MPI_COMM_WORLD, np[0], np[1], &comm_cart_2d) ){
pfft_fprintf(MPI_COMM_WORLD, stderr, "Error: This test file only works with %d processes.\n", np[0]*np[1]);
MPI_Finalize();
return 1;
}
/* Get parameters of data distribution */
alloc_local = pfft_local_size_r2r_3d(n, comm_cart_2d, PFFT_TRANSPOSED_OUT,
local_ni, local_i_start, local_no, local_o_start);
/* Allocate memory */
in = pfft_alloc_real(alloc_local);
out = pfft_alloc_real(alloc_local);
/* Plan parallel forward FFT */
plan_forw = pfft_plan_r2r_3d(
n, in, out, comm_cart_2d, kinds_forw, PFFT_TRANSPOSED_OUT| PFFT_MEASURE| PFFT_DESTROY_INPUT);
/* Plan parallel backward FFT */
plan_back = pfft_plan_r2r_3d(
n, out, in, comm_cart_2d, kinds_back, PFFT_TRANSPOSED_IN| PFFT_MEASURE| PFFT_DESTROY_INPUT);
/* Initialize input with random numbers */
pfft_init_input_real_3d(n, local_ni, local_i_start,
in);
int myrank, size;
MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
// for(int t=0; t<size; t++){
// if(t == myrank){
// int m=0;
// for(int k0=0; k0<local_ni[0]; k0++)
// for(int k1=0; k1<local_ni[1]; k1++){
// for(int k2=0; k2<local_ni[2]; k2++, m++)
// printf("in[%d, %d, %d] = %.2f\t", k0+local_i_start[0], k1+local_i_start[1], k2+local_i_start[2], in[m]);
// printf("\n");
// }
// }
// fflush(stderr);
// MPI_Barrier(MPI_COMM_WORLD);
// }
/* execute parallel forward FFT */
pfft_execute(plan_forw);
// for(int t=0; t<size; t++){
// if(t == myrank){
// int m=0;
// for(int k1=0; k1<local_no[1]; k1++)
// for(int k2=0; k2<local_no[2]; k2++){
// for(int k0=0; k0<local_no[0]; k0++, m++)
// printf("out[%d, %d, %d] = %.2f\t", k0+local_o_start[0], k1+local_o_start[1], k2+local_o_start[2], out[m]);
// printf("\n");
// }
// }
// fflush(stderr);
// MPI_Barrier(MPI_COMM_WORLD);
// }
/* execute parallel backward FFT */
pfft_execute(plan_back);
/* Scale data */
for(ptrdiff_t l=0; l < local_ni[0] * local_ni[1] * local_ni[2]; l++)
in[l] /= (N[0]*N[1]*N[2]);
/* Print error of back transformed data */
MPI_Barrier(MPI_COMM_WORLD);
err = pfft_check_output_real_3d(n, local_ni, local_i_start, in, comm_cart_2d);
pfft_printf(comm_cart_2d, "Error after one forward and backward trafo of size n=(%td, %td, %td):\n", n[0], n[1], n[2]);
pfft_printf(comm_cart_2d, "maxerror = %6.2e;\n", err);
/* free mem and finalize */
pfft_destroy_plan(plan_forw);
pfft_destroy_plan(plan_back);
MPI_Comm_free(&comm_cart_2d);
pfft_free(in); pfft_free(out);
MPI_Finalize();
return 0;
}