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 int main(int argc,char **args) 5 { 6 PetscMPIInt rank,size; 7 PetscInt N0=2048,N1=2048,N2=3,N3=5,N4=5,N=N0*N1; 8 PetscRandom rdm; 9 PetscReal enorm; 10 Vec x,y,z,input,output; 11 Mat A; 12 PetscInt DIM, dim[5],vsize; 13 PetscReal fac; 14 PetscScalar one=1,two=2,three=3; 15 16 PetscFunctionBeginUser; 17 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 18 #if defined(PETSC_USE_COMPLEX) 19 SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers"); 20 #endif 21 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 22 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 23 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(VecSet(input,one)); */ 30 /* PetscCall(VecSetValue(input,1,two,INSERT_VALUES)); */ 31 /* PetscCall(VecSetValue(input,2,three,INSERT_VALUES)); */ 32 /* PetscCall(VecSetValue(input,3,three,INSERT_VALUES)); */ 33 PetscCall(VecSetRandom(input,rdm)); 34 /* PetscCall(VecSetRandom(input,rdm)); */ 35 /* PetscCall(VecSetRandom(input,rdm)); */ 36 PetscCall(VecDuplicate(input,&output)); 37 38 DIM = 2; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4; 39 PetscCall(MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A)); 40 PetscCall(MatCreateVecsFFTW(A,&x,&y,&z)); 41 /* PetscCall(MatCreateVecs(A,&x,&y)); */ 42 /* PetscCall(MatCreateVecs(A,&z,NULL)); */ 43 44 PetscCall(VecGetSize(x,&vsize)); 45 printf("The vector size of input from the main routine is %d\n",vsize); 46 47 PetscCall(VecGetSize(z,&vsize)); 48 printf("The vector size of output from the main routine is %d\n",vsize); 49 50 PetscCall(InputTransformFFT(A,input,x)); 51 52 PetscCall(MatMult(A,x,y)); 53 PetscCall(VecAssemblyBegin(y)); 54 PetscCall(VecAssemblyEnd(y)); 55 PetscCall(VecView(y,PETSC_VIEWER_STDOUT_WORLD)); 56 57 PetscCall(MatMultTranspose(A,y,z)); 58 59 PetscCall(OutputTransformFFT(A,z,output)); 60 fac = 1.0/(PetscReal)N; 61 PetscCall(VecScale(output,fac)); 62 63 PetscCall(VecAssemblyBegin(input)); 64 PetscCall(VecAssemblyEnd(input)); 65 PetscCall(VecAssemblyBegin(output)); 66 PetscCall(VecAssemblyEnd(output)); 67 68 /* PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD)); */ 69 /* PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD)); */ 70 71 PetscCall(VecAXPY(output,-1.0,input)); 72 PetscCall(VecNorm(output,NORM_1,&enorm)); 73 /* if (enorm > 1.e-14) { */ 74 PetscCall(PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm)); 75 /* } */ 76 77 PetscCall(VecDestroy(&output)); 78 PetscCall(VecDestroy(&input)); 79 PetscCall(VecDestroy(&x)); 80 PetscCall(VecDestroy(&y)); 81 PetscCall(VecDestroy(&z)); 82 PetscCall(MatDestroy(&A)); 83 PetscCall(PetscRandomDestroy(&rdm)); 84 PetscCall(PetscFinalize()); 85 return 0; 86 87 } 88