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 int main(int argc,char **args) 6 { 7 PetscMPIInt rank,size; 8 PetscInt N0=4096,N1=4096,N2=256,N3=10,N4=10,N=N0*N1; 9 PetscRandom rdm; 10 PetscReal enorm; 11 Vec x,y,z,input,output; 12 Mat A; 13 PetscInt DIM, dim[5],vsize,row,col; 14 PetscReal fac; 15 16 PetscFunctionBeginUser; 17 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 18 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 19 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 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 PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rdm)); 25 PetscCall(PetscRandomSetFromOptions(rdm)); 26 PetscCall(VecCreate(PETSC_COMM_WORLD,&input)); 27 PetscCall(VecSetSizes(input,PETSC_DECIDE,N)); 28 PetscCall(VecSetFromOptions(input)); 29 PetscCall(VecSetRandom(input,rdm)); 30 PetscCall(VecDuplicate(input,&output)); 31 32 DIM = 2; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4; 33 PetscCall(MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A)); 34 PetscCall(MatGetLocalSize(A,&row,&col)); 35 printf("The Matrix size is %d and %d from process %d\n",row,col,rank); 36 PetscCall(MatCreateVecsFFTW(A,&x,&y,&z)); 37 38 PetscCall(VecGetSize(x,&vsize)); 39 40 PetscCall(VecGetSize(z,&vsize)); 41 printf("The vector size of output from the main routine is %d\n",vsize); 42 43 PetscCall(VecScatterPetscToFFTW(A,input,x)); 44 /*PetscCall(VecDestroy(&input));*/ 45 PetscCall(MatMult(A,x,y)); 46 PetscCall(MatMultTranspose(A,y,z)); 47 PetscCall(VecScatterFFTWToPetsc(A,z,output)); 48 /*PetscCall(VecDestroy(&z));*/ 49 fac = 1.0/(PetscReal)N; 50 PetscCall(VecScale(output,fac)); 51 52 PetscCall(VecAssemblyBegin(input)); 53 PetscCall(VecAssemblyEnd(input)); 54 PetscCall(VecAssemblyBegin(output)); 55 PetscCall(VecAssemblyEnd(output)); 56 57 /* PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD));*/ 58 /* PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD));*/ 59 60 PetscCall(VecAXPY(output,-1.0,input)); 61 PetscCall(VecNorm(output,NORM_1,&enorm)); 62 if (enorm > 1.e-14) { 63 PetscCall(PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm)); 64 } 65 66 PetscCall(VecDestroy(&x)); 67 PetscCall(VecDestroy(&y)); 68 PetscCall(VecDestroy(&z)); 69 PetscCall(VecDestroy(&output)); 70 PetscCall(VecDestroy(&input)); 71 PetscCall(MatDestroy(&A)); 72 PetscCall(PetscRandomDestroy(&rdm)); 73 PetscCall(PetscFinalize()); 74 return 0; 75 76 } 77