1 /* This program illustrates use of paralllel real FFT*/ 2 static char help[]="This program illustrates the use of parallel real 3D fftw (without PETSc interface)"; 3 #include <petscmat.h> 4 #include <fftw3.h> 5 #include <fftw3-mpi.h> 6 7 int main(int argc,char **args) 8 { 9 ptrdiff_t N0=256,N1=256,N2=256,N3=2,dim[4]; 10 fftw_plan bplan,fplan; 11 fftw_complex *out; 12 double *in1,*in2; 13 ptrdiff_t alloc_local,local_n0,local_0_start; 14 ptrdiff_t local_n1,local_1_start; 15 PetscInt i,j,indx,n1; 16 PetscInt size,rank,n,N,*in,N_factor,NM; 17 PetscScalar *data_fin,value1,one=1.57,zero=0.0; 18 PetscScalar a,*x_arr,*y_arr,*z_arr,enorm; 19 Vec fin,fout,fout1,ini,final; 20 PetscRandom rnd; 21 VecScatter vecscat,vecscat1; 22 IS indx1,indx2; 23 PetscInt *indx3,k,l,*indx4; 24 PetscInt low,tempindx,tempindx1; 25 26 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 27 #if defined(PETSC_USE_COMPLEX) 28 SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers. Your current scalar type is complex"); 29 #endif 30 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 31 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 32 33 PetscRandomCreate(PETSC_COMM_WORLD,&rnd); 34 35 alloc_local = fftw_mpi_local_size_3d_transposed(N0,N1,N2/2+1,PETSC_COMM_WORLD,&local_n0,&local_0_start,&local_n1,&local_1_start); 36 37 /* printf("The value alloc_local is %ld from process %d\n",alloc_local,rank); */ 38 printf("The value local_n0 is %ld from process %d\n",local_n0,rank); 39 /* printf("The value local_0_start is %ld from process %d\n",local_0_start,rank);*/ 40 /* printf("The value local_n1 is %ld from process %d\n",local_n1,rank); */ 41 /* printf("The value local_1_start is %ld from process %d\n",local_1_start,rank);*/ 42 43 /* Allocate space for input and output arrays */ 44 45 in1=(double*)fftw_malloc(sizeof(double)*alloc_local*2); 46 in2=(double*)fftw_malloc(sizeof(double)*alloc_local*2); 47 out=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local); 48 49 N=2*N0*N1*(N2/2+1);N_factor=N0*N1*N2; 50 n=2*local_n0*N1*(N2/2+1);n1=local_n1*N0*2*N1; 51 52 /* printf("The value N is %d from process %d\n",N,rank); */ 53 /* printf("The value n is %d from process %d\n",n,rank); */ 54 /* printf("The value n1 is %d from process %d\n",n1,rank); */ 55 /* Creating data vector and accompanying array with VeccreateMPIWithArray */ 56 PetscCall(VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)in1,&fin)); 57 PetscCall(VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)out,&fout)); 58 PetscCall(VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)in2,&fout1)); 59 60 /* VecGetSize(fin,&size); */ 61 /* printf("The size is %d\n",size); */ 62 63 VecSet(fin,one); 64 VecSet(fout,zero); 65 VecSet(fout1,zero); 66 67 VecAssemblyBegin(fin); 68 VecAssemblyEnd(fin); 69 /* VecView(fin,PETSC_VIEWER_STDOUT_WORLD); */ 70 71 VecGetArray(fin,&x_arr); 72 VecGetArray(fout1,&z_arr); 73 VecGetArray(fout,&y_arr); 74 75 fplan=fftw_mpi_plan_dft_r2c_3d(N0,N1,N2,(double*)x_arr,(fftw_complex*)y_arr,PETSC_COMM_WORLD,FFTW_ESTIMATE); 76 bplan=fftw_mpi_plan_dft_c2r_3d(N0,N1,N2,(fftw_complex*)y_arr,(double*)z_arr,PETSC_COMM_WORLD,FFTW_ESTIMATE); 77 78 fftw_execute(fplan); 79 fftw_execute(bplan); 80 81 VecRestoreArray(fin,&x_arr); 82 VecRestoreArray(fout1,&z_arr); 83 VecRestoreArray(fout,&y_arr); 84 85 /* a = 1.0/(PetscReal)N_factor; */ 86 /* PetscCall(VecScale(fout1,a)); */ 87 VecCreate(PETSC_COMM_WORLD,&ini); 88 VecCreate(PETSC_COMM_WORLD,&final); 89 VecSetSizes(ini,local_n0*N1*N2,N_factor); 90 VecSetSizes(final,local_n0*N1*N2,N_factor); 91 /* VecSetSizes(ini,PETSC_DECIDE,N_factor); */ 92 /* VecSetSizes(final,PETSC_DECIDE,N_factor); */ 93 VecSetFromOptions(ini); 94 VecSetFromOptions(final); 95 96 if (N2%2==0) NM=N2+2; 97 else NM=N2+1; 98 99 PetscCall(VecGetOwnershipRange(fin,&low,NULL)); 100 printf("The local index is %d from %d\n",low,rank); 101 PetscCall(PetscMalloc1(local_n0*N1*N2,&indx3)); 102 PetscCall(PetscMalloc1(local_n0*N1*N2,&indx4)); 103 for (i=0; i<local_n0; i++) { 104 for (j=0;j<N1;j++) { 105 for (k=0;k<N2;k++) { 106 tempindx = i*N1*N2 + j*N2 + k; 107 tempindx1 = i*N1*NM + j*NM + k; 108 109 indx3[tempindx]=local_0_start*N1*N2+tempindx; 110 indx4[tempindx]=low+tempindx1; 111 } 112 /* printf("index3 %d from proc %d is \n",indx3[tempindx],rank); */ 113 /* printf("index4 %d from proc %d is \n",indx4[tempindx],rank); */ 114 } 115 } 116 VecGetValues(fin,local_n0*N1*N2,indx4,x_arr); 117 VecSetValues(ini,local_n0*N1*N2,indx3,x_arr,INSERT_VALUES); 118 VecAssemblyBegin(ini); 119 VecAssemblyEnd(ini); 120 121 VecGetValues(fout1,local_n0*N1*N2,indx4,y_arr); 122 VecSetValues(final,local_n0*N1*N2,indx3,y_arr,INSERT_VALUES); 123 VecAssemblyBegin(final); 124 VecAssemblyEnd(final); 125 126 printf("The local index value is %ld from %d",local_n0*N1*N2,rank); 127 /* 128 for (i=0;i<N0;i++) { 129 for (j=0;j<N1;j++) { 130 indx=i*N1*NM+j*NM; 131 ISCreateStride(PETSC_COMM_WORLD,N2,indx,1,&indx1); 132 indx=i*N1*N2+j*N2; 133 ISCreateStride(PETSC_COMM_WORLD,N2,indx,1,&indx2); 134 VecScatterCreate(fin,indx1,ini,indx2,&vecscat); 135 VecScatterBegin(vecscat,fin,ini,INSERT_VALUES,SCATTER_FORWARD); 136 VecScatterEnd(vecscat,fin,ini,INSERT_VALUES,SCATTER_FORWARD); 137 VecScatterCreate(fout1,indx1,final,indx2,&vecscat1); 138 VecScatterBegin(vecscat1,fout1,final,INSERT_VALUES,SCATTER_FORWARD); 139 VecScatterEnd(vecscat1,fout1,final,INSERT_VALUES,SCATTER_FORWARD); 140 } 141 } 142 */ 143 a = 1.0/(PetscReal)N_factor; 144 PetscCall(VecScale(fout1,a)); 145 PetscCall(VecScale(final,a)); 146 147 VecAssemblyBegin(ini); 148 VecAssemblyEnd(ini); 149 150 VecAssemblyBegin(final); 151 VecAssemblyEnd(final); 152 153 /* VecView(final,PETSC_VIEWER_STDOUT_WORLD); */ 154 PetscCall(VecAXPY(final,-1.0,ini)); 155 PetscCall(VecNorm(final,NORM_1,&enorm)); 156 PetscCall(PetscPrintf(PETSC_COMM_WORLD," Error norm of |x - z| = %e\n",enorm)); 157 fftw_destroy_plan(fplan); 158 fftw_destroy_plan(bplan); 159 fftw_free(in1); PetscCall(VecDestroy(&fin)); 160 fftw_free(out); PetscCall(VecDestroy(&fout)); 161 fftw_free(in2); PetscCall(VecDestroy(&fout1)); 162 163 PetscCall(PetscFinalize()); 164 return 0; 165 } 166