1c4762a1bSJed Brown static char help[]="This program illustrates the use of PETSc-fftw interface for real DFT\n"; 2c4762a1bSJed Brown #include <petscmat.h> 3c4762a1bSJed Brown #include <fftw3-mpi.h> 4c4762a1bSJed Brown 5c4762a1bSJed Brown extern PetscErrorCode InputTransformFFT(Mat,Vec,Vec); 6c4762a1bSJed Brown extern PetscErrorCode OutputTransformFFT(Mat,Vec,Vec); 7ad0e0ea3SStefano Zampini int main(int argc,char **args) 8c4762a1bSJed Brown { 9c4762a1bSJed Brown PetscMPIInt rank,size; 10c4762a1bSJed Brown PetscInt N0=3,N1=3,N2=3,N=N0*N1*N2; 11c4762a1bSJed Brown PetscRandom rdm; 12c4762a1bSJed Brown PetscScalar a; 13c4762a1bSJed Brown PetscReal enorm; 14c4762a1bSJed Brown Vec x,y,z,input,output; 15c4762a1bSJed Brown PetscBool view=PETSC_FALSE,use_interface=PETSC_TRUE; 16c4762a1bSJed Brown Mat A; 17c4762a1bSJed Brown PetscInt DIM, dim[3],vsize; 18c4762a1bSJed Brown PetscReal fac; 19c4762a1bSJed Brown 20*9566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 21c4762a1bSJed Brown #if defined(PETSC_USE_COMPLEX) 22c4762a1bSJed Brown SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers"); 23c4762a1bSJed Brown #endif 24c4762a1bSJed Brown 25*9566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 26*9566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 27c4762a1bSJed Brown 28*9566063dSJacob Faibussowitsch PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rdm)); 29*9566063dSJacob Faibussowitsch PetscCall(PetscRandomSetFromOptions(rdm)); 30c4762a1bSJed Brown 31*9566063dSJacob Faibussowitsch PetscCall(VecCreate(PETSC_COMM_WORLD,&input)); 32*9566063dSJacob Faibussowitsch PetscCall(VecSetSizes(input,PETSC_DECIDE,N)); 33*9566063dSJacob Faibussowitsch PetscCall(VecSetFromOptions(input)); 34*9566063dSJacob Faibussowitsch PetscCall(VecSetRandom(input,rdm)); 35*9566063dSJacob Faibussowitsch PetscCall(VecDuplicate(input,&output)); 36*9566063dSJacob Faibussowitsch /* PetscCall(VecGetSize(input,&vsize)); */ 37c4762a1bSJed Brown /* printf("Size of the input Vector is %d\n",vsize); */ 38c4762a1bSJed Brown 39c4762a1bSJed Brown DIM = 3; 40c4762a1bSJed Brown dim[0] = N0; dim[1] = N1; dim[2] = N2; 41c4762a1bSJed Brown 42*9566063dSJacob Faibussowitsch PetscCall(MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A)); 43*9566063dSJacob Faibussowitsch PetscCall(MatCreateVecs(A,&x,&y)); 44*9566063dSJacob Faibussowitsch PetscCall(MatCreateVecs(A,&z,NULL)); 45*9566063dSJacob Faibussowitsch PetscCall(VecGetSize(y,&vsize)); 46c4762a1bSJed Brown printf("The vector size from the main routine is %d\n",vsize); 47c4762a1bSJed Brown 48*9566063dSJacob Faibussowitsch PetscCall(InputTransformFFT(A,input,x)); 49*9566063dSJacob Faibussowitsch PetscCall(MatMult(A,x,y)); 50*9566063dSJacob Faibussowitsch PetscCall(MatMultTranspose(A,y,z)); 51*9566063dSJacob Faibussowitsch PetscCall(OutputTransformFFT(A,z,output)); 52c4762a1bSJed Brown 53c4762a1bSJed Brown fac = 1.0/(PetscReal)N; 54*9566063dSJacob Faibussowitsch PetscCall(VecScale(output,fac)); 55c4762a1bSJed Brown 56*9566063dSJacob Faibussowitsch PetscCall(VecAssemblyBegin(input)); 57*9566063dSJacob Faibussowitsch PetscCall(VecAssemblyEnd(input)); 58*9566063dSJacob Faibussowitsch PetscCall(VecAssemblyBegin(output)); 59*9566063dSJacob Faibussowitsch PetscCall(VecAssemblyEnd(output)); 60c4762a1bSJed Brown 61*9566063dSJacob Faibussowitsch PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD)); 62*9566063dSJacob Faibussowitsch PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD)); 63c4762a1bSJed Brown 64*9566063dSJacob Faibussowitsch PetscCall(VecAXPY(output,-1.0,input)); 65*9566063dSJacob Faibussowitsch PetscCall(VecNorm(output,NORM_1,&enorm)); 66c4762a1bSJed Brown /* if (enorm > 1.e-14) { */ 67dd400576SPatrick Sanan if (rank == 0) { 68*9566063dSJacob Faibussowitsch PetscCall(PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm)); 69c4762a1bSJed Brown } 70c4762a1bSJed Brown /* } */ 71c4762a1bSJed Brown 72*9566063dSJacob Faibussowitsch /* PetscCall(MatCreateVecs(A,&z,NULL)); */ 73c4762a1bSJed Brown /* printf("Vector size from ex148 %d\n",vsize); */ 74*9566063dSJacob Faibussowitsch /* PetscCall(PetscObjectSetName((PetscObject) x, "Real space vector")); */ 75*9566063dSJacob Faibussowitsch /* PetscCall(PetscObjectSetName((PetscObject) y, "Frequency space vector")); */ 76*9566063dSJacob Faibussowitsch /* PetscCall(PetscObjectSetName((PetscObject) z, "Reconstructed vector")); */ 77c4762a1bSJed Brown 78*9566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 79b122ec5aSJacob Faibussowitsch return 0; 80c4762a1bSJed Brown 81c4762a1bSJed Brown } 82