Actual source code: ex154.c
1: static char help[]="This program illustrates the use of PETSc-fftw interface for Complex parallel DFT\n";
2: #include <petscmat.h>
3: #include <fftw3-mpi.h>
8: PetscInt main(PetscInt argc,char **args)
9: {
10: PetscErrorCode ierr;
11: PetscMPIInt rank,size;
12: PetscInt N0=500,N1=5,N2=5,N3=10,N4=10,N=N0;
13: PetscRandom rdm;
14: PetscReal enorm;
15: Vec x,y,z,input,output;
16: Mat A;
17: PetscInt DIM, dim[5],vsize;
18: PetscReal fac;
20: PetscInitialize(&argc,&args,(char *)0,help);
21: MPI_Comm_size(PETSC_COMM_WORLD, &size);
22: MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
23: #if !defined(PETSC_USE_COMPLEX)
24: SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires complex numbers");
25: #endif
26: PetscRandomCreate(PETSC_COMM_WORLD, &rdm);
27: PetscRandomSetFromOptions(rdm);
28: VecCreate(PETSC_COMM_WORLD,&input);
29: VecSetSizes(input,PETSC_DECIDE,N);
30: VecSetFromOptions(input);
31: VecSetRandom(input,rdm);
32: VecAssemblyBegin(input);
33: VecAssemblyEnd(input);
34: // VecView(input,PETSC_VIEWER_STDOUT_WORLD);
35: VecDuplicate(input,&output);
36:
37: DIM = 1; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4;
38: MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A);
39: // MatGetVecs(A,&x,&y,&z);
40: MatGetVecs(A,&x,&y);
41: MatGetVecs(A,&z,PETSC_NULL);
43: VecGetSize(x,&vsize);
44: printf("The vector size of input from the main routine is %d\n",vsize);
46: VecGetSize(input,&vsize);
47: printf("The vector size of output from the main routine is %d\n",vsize);
49: InputTransformFFT(A,input,x);
50: // VecAssemblyBegin(x);
51: // VecAssemblyEnd(x);
52: // VecView(x,PETSC_VIEWER_STDOUT_WORLD);
54: MatMult(A,x,y);
55: MatMultTranspose(A,y,z);
57: OutputTransformFFT(A,z,output);
58: fac = 1.0/(PetscReal)N;
59: VecScale(output,fac);
60:
61: // VecAssemblyBegin(input);
62: // VecAssemblyEnd(input);
63: // VecAssemblyBegin(output);
64: // VecAssemblyEnd(output);
66: // VecView(input,PETSC_VIEWER_STDOUT_WORLD);
67: // VecView(output,PETSC_VIEWER_STDOUT_WORLD);
69: VecAXPY(output,-1.0,input);
70: VecNorm(output,NORM_1,&enorm);
71: // if (enorm > 1.e-14){
72: PetscPrintf(PETSC_COMM_SELF," Error norm of |x - z| %e\n",enorm);
73: // }
74: VecDestroy(&output);
75: VecDestroy(&input);
76: VecDestroy(&x);
77: VecDestroy(&y);
78: VecDestroy(&z);
79: MatDestroy(&A);
80: PetscRandomDestroy(&rdm);
81: PetscFinalize();
82: return 0;
83: }