1*c4762a1bSJed Brown static char help[]="This program illustrates the use of PETSc-fftw interface for real DFT\n"; 2*c4762a1bSJed Brown #include <petscmat.h> 3*c4762a1bSJed Brown #include <fftw3-mpi.h> 4*c4762a1bSJed Brown 5*c4762a1bSJed Brown extern PetscErrorCode InputTransformFFT(Mat,Vec,Vec); 6*c4762a1bSJed Brown extern PetscErrorCode OutputTransformFFT(Mat,Vec,Vec); 7*c4762a1bSJed Brown PetscInt main(PetscInt argc,char **args) 8*c4762a1bSJed Brown { 9*c4762a1bSJed Brown PetscErrorCode ierr; 10*c4762a1bSJed Brown PetscMPIInt rank,size; 11*c4762a1bSJed Brown PetscInt N0=3,N1=3,N2=3,N=N0*N1*N2; 12*c4762a1bSJed Brown PetscRandom rdm; 13*c4762a1bSJed Brown PetscScalar a; 14*c4762a1bSJed Brown PetscReal enorm; 15*c4762a1bSJed Brown Vec x,y,z,input,output; 16*c4762a1bSJed Brown PetscBool view=PETSC_FALSE,use_interface=PETSC_TRUE; 17*c4762a1bSJed Brown Mat A; 18*c4762a1bSJed Brown PetscInt DIM, dim[3],vsize; 19*c4762a1bSJed Brown PetscReal fac; 20*c4762a1bSJed Brown 21*c4762a1bSJed Brown ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 22*c4762a1bSJed Brown #if defined(PETSC_USE_COMPLEX) 23*c4762a1bSJed Brown SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers"); 24*c4762a1bSJed Brown #endif 25*c4762a1bSJed Brown 26*c4762a1bSJed Brown ierr = MPI_Comm_size(PETSC_COMM_WORLD, &size);CHKERRQ(ierr); 27*c4762a1bSJed Brown ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &rank);CHKERRQ(ierr); 28*c4762a1bSJed Brown 29*c4762a1bSJed Brown 30*c4762a1bSJed Brown ierr = PetscRandomCreate(PETSC_COMM_WORLD, &rdm);CHKERRQ(ierr); 31*c4762a1bSJed Brown ierr = PetscRandomSetFromOptions(rdm);CHKERRQ(ierr); 32*c4762a1bSJed Brown 33*c4762a1bSJed Brown ierr = VecCreate(PETSC_COMM_WORLD,&input);CHKERRQ(ierr); 34*c4762a1bSJed Brown ierr = VecSetSizes(input,PETSC_DECIDE,N);CHKERRQ(ierr); 35*c4762a1bSJed Brown ierr = VecSetFromOptions(input);CHKERRQ(ierr); 36*c4762a1bSJed Brown ierr = VecSetRandom(input,rdm);CHKERRQ(ierr); 37*c4762a1bSJed Brown ierr = VecDuplicate(input,&output); 38*c4762a1bSJed Brown /* ierr = VecGetSize(input,&vsize);CHKERRQ(ierr); */ 39*c4762a1bSJed Brown /* printf("Size of the input Vector is %d\n",vsize); */ 40*c4762a1bSJed Brown 41*c4762a1bSJed Brown DIM = 3; 42*c4762a1bSJed Brown dim[0] = N0; dim[1] = N1; dim[2] = N2; 43*c4762a1bSJed Brown 44*c4762a1bSJed Brown ierr = MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A);CHKERRQ(ierr); 45*c4762a1bSJed Brown ierr = MatCreateVecs(A,&x,&y);CHKERRQ(ierr); 46*c4762a1bSJed Brown ierr = MatCreateVecs(A,&z,NULL);CHKERRQ(ierr); 47*c4762a1bSJed Brown ierr = VecGetSize(y,&vsize);CHKERRQ(ierr); 48*c4762a1bSJed Brown printf("The vector size from the main routine is %d\n",vsize); 49*c4762a1bSJed Brown 50*c4762a1bSJed Brown ierr = InputTransformFFT(A,input,x);CHKERRQ(ierr); 51*c4762a1bSJed Brown ierr = MatMult(A,x,y);CHKERRQ(ierr); 52*c4762a1bSJed Brown ierr = MatMultTranspose(A,y,z);CHKERRQ(ierr); 53*c4762a1bSJed Brown ierr = OutputTransformFFT(A,z,output);CHKERRQ(ierr); 54*c4762a1bSJed Brown 55*c4762a1bSJed Brown fac = 1.0/(PetscReal)N; 56*c4762a1bSJed Brown ierr = VecScale(output,fac);CHKERRQ(ierr); 57*c4762a1bSJed Brown 58*c4762a1bSJed Brown ierr = VecAssemblyBegin(input);CHKERRQ(ierr); 59*c4762a1bSJed Brown ierr = VecAssemblyEnd(input);CHKERRQ(ierr); 60*c4762a1bSJed Brown ierr = VecAssemblyBegin(output);CHKERRQ(ierr); 61*c4762a1bSJed Brown ierr = VecAssemblyEnd(output);CHKERRQ(ierr); 62*c4762a1bSJed Brown 63*c4762a1bSJed Brown ierr = VecView(input,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 64*c4762a1bSJed Brown ierr = VecView(output,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 65*c4762a1bSJed Brown 66*c4762a1bSJed Brown ierr = VecAXPY(output,-1.0,input);CHKERRQ(ierr); 67*c4762a1bSJed Brown ierr = VecNorm(output,NORM_1,&enorm);CHKERRQ(ierr); 68*c4762a1bSJed Brown /* if (enorm > 1.e-14) { */ 69*c4762a1bSJed Brown if (!rank) { 70*c4762a1bSJed Brown ierr = PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm);CHKERRQ(ierr); 71*c4762a1bSJed Brown } 72*c4762a1bSJed Brown /* } */ 73*c4762a1bSJed Brown 74*c4762a1bSJed Brown 75*c4762a1bSJed Brown 76*c4762a1bSJed Brown 77*c4762a1bSJed Brown /* ierr = MatCreateVecs(A,&z,NULL);CHKERRQ(ierr); */ 78*c4762a1bSJed Brown /* printf("Vector size from ex148 %d\n",vsize); */ 79*c4762a1bSJed Brown /* ierr = PetscObjectSetName((PetscObject) x, "Real space vector");CHKERRQ(ierr); */ 80*c4762a1bSJed Brown /* ierr = PetscObjectSetName((PetscObject) y, "Frequency space vector");CHKERRQ(ierr); */ 81*c4762a1bSJed Brown /* ierr = PetscObjectSetName((PetscObject) z, "Reconstructed vector");CHKERRQ(ierr); */ 82*c4762a1bSJed Brown 83*c4762a1bSJed Brown ierr = PetscFinalize(); 84*c4762a1bSJed Brown return ierr; 85*c4762a1bSJed Brown 86*c4762a1bSJed Brown } 87*c4762a1bSJed Brown 88*c4762a1bSJed Brown 89*c4762a1bSJed Brown 90