Actual source code: ex155.c
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;
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));
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));
32: DIM = 2;
33: dim[0] = N0;
34: dim[1] = N1;
35: dim[2] = N2;
36: dim[3] = N3;
37: dim[4] = N4;
38: PetscCall(MatCreateFFT(PETSC_COMM_WORLD, DIM, dim, MATFFTW, &A));
39: PetscCall(MatGetLocalSize(A, &row, &col));
40: printf("The Matrix size is %d and %d from process %d\n", row, col, rank);
41: PetscCall(MatCreateVecsFFTW(A, &x, &y, &z));
43: PetscCall(VecGetSize(x, &vsize));
45: PetscCall(VecGetSize(z, &vsize));
46: printf("The vector size of output from the main routine is %d\n", vsize);
48: PetscCall(VecScatterPetscToFFTW(A, input, x));
49: /*PetscCall(VecDestroy(&input));*/
50: PetscCall(MatMult(A, x, y));
51: PetscCall(MatMultTranspose(A, y, z));
52: PetscCall(VecScatterFFTWToPetsc(A, z, output));
53: /*PetscCall(VecDestroy(&z));*/
54: fac = 1.0 / (PetscReal)N;
55: PetscCall(VecScale(output, fac));
57: PetscCall(VecAssemblyBegin(input));
58: PetscCall(VecAssemblyEnd(input));
59: PetscCall(VecAssemblyBegin(output));
60: PetscCall(VecAssemblyEnd(output));
62: /* PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD));*/
63: /* PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD));*/
65: PetscCall(VecAXPY(output, -1.0, input));
66: PetscCall(VecNorm(output, NORM_1, &enorm));
67: if (enorm > 1.e-14) PetscCall(PetscPrintf(PETSC_COMM_SELF, " Error norm of |x - z| %e\n", enorm));
69: PetscCall(VecDestroy(&x));
70: PetscCall(VecDestroy(&y));
71: PetscCall(VecDestroy(&z));
72: PetscCall(VecDestroy(&output));
73: PetscCall(VecDestroy(&input));
74: PetscCall(MatDestroy(&A));
75: PetscCall(PetscRandomDestroy(&rdm));
76: PetscCall(PetscFinalize());
77: return 0;
78: }