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 PetscMPIInt rank, size; 7 PetscInt N0 = 4096, N1 = 4096, N2 = 256, N3 = 10, N4 = 10, 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, row, col; 13 PetscReal fac; 14 15 PetscFunctionBeginUser; 16 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 17 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 18 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 19 20 #if defined(PETSC_USE_COMPLEX) 21 SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_SUP, "Example for Real DFT. Your current data type is complex!"); 22 #endif 23 PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rdm)); 24 PetscCall(PetscRandomSetFromOptions(rdm)); 25 PetscCall(VecCreate(PETSC_COMM_WORLD, &input)); 26 PetscCall(VecSetSizes(input, PETSC_DECIDE, N)); 27 PetscCall(VecSetFromOptions(input)); 28 PetscCall(VecSetRandom(input, rdm)); 29 PetscCall(VecDuplicate(input, &output)); 30 31 DIM = 2; 32 dim[0] = N0; 33 dim[1] = N1; 34 dim[2] = N2; 35 dim[3] = N3; 36 dim[4] = N4; 37 PetscCall(MatCreateFFT(PETSC_COMM_WORLD, DIM, dim, MATFFTW, &A)); 38 PetscCall(MatGetLocalSize(A, &row, &col)); 39 printf("The Matrix size is %d and %d from process %d\n", row, col, rank); 40 PetscCall(MatCreateVecsFFTW(A, &x, &y, &z)); 41 42 PetscCall(VecGetSize(x, &vsize)); 43 44 PetscCall(VecGetSize(z, &vsize)); 45 printf("The vector size of output from the main routine is %d\n", vsize); 46 47 PetscCall(VecScatterPetscToFFTW(A, input, x)); 48 /*PetscCall(VecDestroy(&input));*/ 49 PetscCall(MatMult(A, x, y)); 50 PetscCall(MatMultTranspose(A, y, z)); 51 PetscCall(VecScatterFFTWToPetsc(A, z, output)); 52 /*PetscCall(VecDestroy(&z));*/ 53 fac = 1.0 / (PetscReal)N; 54 PetscCall(VecScale(output, fac)); 55 56 PetscCall(VecAssemblyBegin(input)); 57 PetscCall(VecAssemblyEnd(input)); 58 PetscCall(VecAssemblyBegin(output)); 59 PetscCall(VecAssemblyEnd(output)); 60 61 /* PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD));*/ 62 /* PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD));*/ 63 64 PetscCall(VecAXPY(output, -1.0, input)); 65 PetscCall(VecNorm(output, NORM_1, &enorm)); 66 if (enorm > 1.e-14) { PetscCall(PetscPrintf(PETSC_COMM_SELF, " Error norm of |x - z| %e\n", enorm)); } 67 68 PetscCall(VecDestroy(&x)); 69 PetscCall(VecDestroy(&y)); 70 PetscCall(VecDestroy(&z)); 71 PetscCall(VecDestroy(&output)); 72 PetscCall(VecDestroy(&input)); 73 PetscCall(MatDestroy(&A)); 74 PetscCall(PetscRandomDestroy(&rdm)); 75 PetscCall(PetscFinalize()); 76 return 0; 77 } 78