1 static char help[]="This program illustrates the use of PETSc-fftw interface for parallel real DFT\n"; 2 #include <petscmat.h> 3 #include <fftw3-mpi.h> 4 /*extern PetscErrorCode MatCreateVecsFFT(Mat,Vec *,Vec *,Vec *);*/ 5 PetscInt main(PetscInt argc,char **args) 6 { 7 PetscErrorCode ierr; 8 PetscMPIInt rank,size; 9 PetscInt N0=4096,N1=4096,N2=256,N3=10,N4=10,N=N0*N1; 10 PetscRandom rdm; 11 PetscReal enorm; 12 Vec x,y,z,input,output; 13 Mat A; 14 PetscInt DIM, dim[5],vsize,row,col; 15 PetscReal fac; 16 17 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 18 ierr = MPI_Comm_size(PETSC_COMM_WORLD, &size);CHKERRQ(ierr); 19 ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &rank);CHKERRQ(ierr); 20 21 #if defined(PETSC_USE_COMPLEX) 22 SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "Example for Real DFT. Your current data type is complex!"); 23 #endif 24 ierr = PetscRandomCreate(PETSC_COMM_WORLD, &rdm);CHKERRQ(ierr); 25 ierr = PetscRandomSetFromOptions(rdm);CHKERRQ(ierr); 26 ierr = VecCreate(PETSC_COMM_WORLD,&input);CHKERRQ(ierr); 27 ierr = VecSetSizes(input,PETSC_DECIDE,N);CHKERRQ(ierr); 28 ierr = VecSetFromOptions(input);CHKERRQ(ierr); 29 ierr = VecSetRandom(input,rdm);CHKERRQ(ierr); 30 ierr = VecDuplicate(input,&output); 31 32 DIM = 2; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4; 33 ierr = MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A);CHKERRQ(ierr); 34 ierr = MatGetLocalSize(A,&row,&col);CHKERRQ(ierr); 35 printf("The Matrix size is %d and %d from process %d\n",row,col,rank); 36 ierr = MatCreateVecsFFTW(A,&x,&y,&z);CHKERRQ(ierr); 37 38 ierr = VecGetSize(x,&vsize);CHKERRQ(ierr); 39 40 ierr = VecGetSize(z,&vsize);CHKERRQ(ierr); 41 printf("The vector size of output from the main routine is %d\n",vsize); 42 43 ierr = VecScatterPetscToFFTW(A,input,x);CHKERRQ(ierr); 44 /*ierr = VecDestroy(&input);CHKERRQ(ierr);*/ 45 ierr = MatMult(A,x,y);CHKERRQ(ierr); 46 ierr = MatMultTranspose(A,y,z);CHKERRQ(ierr); 47 ierr = VecScatterFFTWToPetsc(A,z,output);CHKERRQ(ierr); 48 /*ierr = VecDestroy(&z);CHKERRQ(ierr);*/ 49 fac = 1.0/(PetscReal)N; 50 ierr = VecScale(output,fac);CHKERRQ(ierr); 51 52 ierr = VecAssemblyBegin(input);CHKERRQ(ierr); 53 ierr = VecAssemblyEnd(input);CHKERRQ(ierr); 54 ierr = VecAssemblyBegin(output);CHKERRQ(ierr); 55 ierr = VecAssemblyEnd(output);CHKERRQ(ierr); 56 57 /* ierr = VecView(input,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);*/ 58 /* ierr = VecView(output,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);*/ 59 60 ierr = VecAXPY(output,-1.0,input);CHKERRQ(ierr); 61 ierr = VecNorm(output,NORM_1,&enorm);CHKERRQ(ierr); 62 if (enorm > 1.e-14) { 63 ierr = PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm);CHKERRQ(ierr); 64 } 65 66 ierr = VecDestroy(&x);CHKERRQ(ierr); 67 ierr = VecDestroy(&y);CHKERRQ(ierr); 68 ierr = VecDestroy(&z);CHKERRQ(ierr); 69 ierr = VecDestroy(&output);CHKERRQ(ierr); 70 ierr = VecDestroy(&input);CHKERRQ(ierr); 71 ierr = MatDestroy(&A);CHKERRQ(ierr); 72 ierr = PetscRandomDestroy(&rdm);CHKERRQ(ierr); 73 ierr = PetscFinalize(); 74 return ierr; 75 76 } 77