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 PetscErrorCode ierr; 22 VecScatter vecscat,vecscat1; 23 IS indx1,indx2; 24 PetscInt *indx3,k,l,*indx4; 25 PetscInt low,tempindx,tempindx1; 26 27 28 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 29 #if defined(PETSC_USE_COMPLEX) 30 SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers. Your current scalar type is complex"); 31 #endif 32 ierr = MPI_Comm_size(PETSC_COMM_WORLD, &size);CHKERRMPI(ierr); 33 ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &rank);CHKERRMPI(ierr); 34 35 PetscRandomCreate(PETSC_COMM_WORLD,&rnd); 36 37 38 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); 39 40 /* printf("The value alloc_local is %ld from process %d\n",alloc_local,rank); */ 41 printf("The value local_n0 is %ld from process %d\n",local_n0,rank); 42 /* printf("The value local_0_start is %ld from process %d\n",local_0_start,rank);*/ 43 /* printf("The value local_n1 is %ld from process %d\n",local_n1,rank); */ 44 /* printf("The value local_1_start is %ld from process %d\n",local_1_start,rank);*/ 45 46 /* Allocate space for input and output arrays */ 47 48 in1=(double*)fftw_malloc(sizeof(double)*alloc_local*2); 49 in2=(double*)fftw_malloc(sizeof(double)*alloc_local*2); 50 out=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local); 51 52 53 N=2*N0*N1*(N2/2+1);N_factor=N0*N1*N2; 54 n=2*local_n0*N1*(N2/2+1);n1=local_n1*N0*2*N1; 55 56 /* printf("The value N is %d from process %d\n",N,rank); */ 57 /* printf("The value n is %d from process %d\n",n,rank); */ 58 /* printf("The value n1 is %d from process %d\n",n1,rank); */ 59 /* Creating data vector and accompanying array with VeccreateMPIWithArray */ 60 ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)in1,&fin);CHKERRQ(ierr); 61 ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)out,&fout);CHKERRQ(ierr); 62 ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,1,n,N,(PetscScalar*)in2,&fout1);CHKERRQ(ierr); 63 64 /* VecGetSize(fin,&size); */ 65 /* printf("The size is %d\n",size); */ 66 67 VecSet(fin,one); 68 VecSet(fout,zero); 69 VecSet(fout1,zero); 70 71 VecAssemblyBegin(fin); 72 VecAssemblyEnd(fin); 73 /* VecView(fin,PETSC_VIEWER_STDOUT_WORLD); */ 74 75 76 VecGetArray(fin,&x_arr); 77 VecGetArray(fout1,&z_arr); 78 VecGetArray(fout,&y_arr); 79 80 fplan=fftw_mpi_plan_dft_r2c_3d(N0,N1,N2,(double*)x_arr,(fftw_complex*)y_arr,PETSC_COMM_WORLD,FFTW_ESTIMATE); 81 bplan=fftw_mpi_plan_dft_c2r_3d(N0,N1,N2,(fftw_complex*)y_arr,(double*)z_arr,PETSC_COMM_WORLD,FFTW_ESTIMATE); 82 83 fftw_execute(fplan); 84 fftw_execute(bplan); 85 86 VecRestoreArray(fin,&x_arr); 87 VecRestoreArray(fout1,&z_arr); 88 VecRestoreArray(fout,&y_arr); 89 90 91 /* a = 1.0/(PetscReal)N_factor; */ 92 /* ierr = VecScale(fout1,a);CHKERRQ(ierr); */ 93 VecCreate(PETSC_COMM_WORLD,&ini); 94 VecCreate(PETSC_COMM_WORLD,&final); 95 VecSetSizes(ini,local_n0*N1*N2,N_factor); 96 VecSetSizes(final,local_n0*N1*N2,N_factor); 97 /* VecSetSizes(ini,PETSC_DECIDE,N_factor); */ 98 /* VecSetSizes(final,PETSC_DECIDE,N_factor); */ 99 VecSetFromOptions(ini); 100 VecSetFromOptions(final); 101 102 if (N2%2==0) NM=N2+2; 103 else NM=N2+1; 104 105 ierr = VecGetOwnershipRange(fin,&low,NULL); 106 printf("The local index is %d from %d\n",low,rank); 107 ierr = PetscMalloc1(local_n0*N1*N2,&indx3); 108 ierr = PetscMalloc1(local_n0*N1*N2,&indx4); 109 for (i=0; i<local_n0; i++) { 110 for (j=0;j<N1;j++) { 111 for (k=0;k<N2;k++) { 112 tempindx = i*N1*N2 + j*N2 + k; 113 tempindx1 = i*N1*NM + j*NM + k; 114 115 indx3[tempindx]=local_0_start*N1*N2+tempindx; 116 indx4[tempindx]=low+tempindx1; 117 } 118 /* printf("index3 %d from proc %d is \n",indx3[tempindx],rank); */ 119 /* printf("index4 %d from proc %d is \n",indx4[tempindx],rank); */ 120 } 121 } 122 VecGetValues(fin,local_n0*N1*N2,indx4,x_arr); 123 VecSetValues(ini,local_n0*N1*N2,indx3,x_arr,INSERT_VALUES); 124 VecAssemblyBegin(ini); 125 VecAssemblyEnd(ini); 126 127 VecGetValues(fout1,local_n0*N1*N2,indx4,y_arr); 128 VecSetValues(final,local_n0*N1*N2,indx3,y_arr,INSERT_VALUES); 129 VecAssemblyBegin(final); 130 VecAssemblyEnd(final); 131 132 printf("The local index value is %ld from %d",local_n0*N1*N2,rank); 133 /* 134 for (i=0;i<N0;i++) { 135 for (j=0;j<N1;j++) { 136 indx=i*N1*NM+j*NM; 137 ISCreateStride(PETSC_COMM_WORLD,N2,indx,1,&indx1); 138 indx=i*N1*N2+j*N2; 139 ISCreateStride(PETSC_COMM_WORLD,N2,indx,1,&indx2); 140 VecScatterCreate(fin,indx1,ini,indx2,&vecscat); 141 VecScatterBegin(vecscat,fin,ini,INSERT_VALUES,SCATTER_FORWARD); 142 VecScatterEnd(vecscat,fin,ini,INSERT_VALUES,SCATTER_FORWARD); 143 VecScatterCreate(fout1,indx1,final,indx2,&vecscat1); 144 VecScatterBegin(vecscat1,fout1,final,INSERT_VALUES,SCATTER_FORWARD); 145 VecScatterEnd(vecscat1,fout1,final,INSERT_VALUES,SCATTER_FORWARD); 146 } 147 } 148 */ 149 a = 1.0/(PetscReal)N_factor; 150 ierr = VecScale(fout1,a);CHKERRQ(ierr); 151 ierr = VecScale(final,a);CHKERRQ(ierr); 152 153 VecAssemblyBegin(ini); 154 VecAssemblyEnd(ini); 155 156 VecAssemblyBegin(final); 157 VecAssemblyEnd(final); 158 159 /* VecView(final,PETSC_VIEWER_STDOUT_WORLD); */ 160 ierr = VecAXPY(final,-1.0,ini);CHKERRQ(ierr); 161 ierr = VecNorm(final,NORM_1,&enorm);CHKERRQ(ierr); 162 ierr = PetscPrintf(PETSC_COMM_WORLD," Error norm of |x - z| = %e\n",enorm);CHKERRQ(ierr); 163 fftw_destroy_plan(fplan); 164 fftw_destroy_plan(bplan); 165 fftw_free(in1); ierr = VecDestroy(&fin);CHKERRQ(ierr); 166 fftw_free(out); ierr = VecDestroy(&fout);CHKERRQ(ierr); 167 fftw_free(in2); ierr = VecDestroy(&fout1);CHKERRQ(ierr); 168 169 ierr = PetscFinalize(); 170 return ierr; 171 } 172