xref: /petsc/src/mat/tests/ex155.c (revision 9566063d113dddea24716c546802770db7481bc0)
1c4762a1bSJed Brown static char help[]="This program illustrates the use of PETSc-fftw interface for parallel real DFT\n";
2c4762a1bSJed Brown #include <petscmat.h>
3c4762a1bSJed Brown #include <fftw3-mpi.h>
4c4762a1bSJed Brown /*extern PetscErrorCode MatCreateVecsFFT(Mat,Vec *,Vec *,Vec *);*/
5ad0e0ea3SStefano Zampini int main(int argc,char **args)
6c4762a1bSJed Brown {
7c4762a1bSJed Brown   PetscMPIInt    rank,size;
8c4762a1bSJed Brown   PetscInt       N0=4096,N1=4096,N2=256,N3=10,N4=10,N=N0*N1;
9c4762a1bSJed Brown   PetscRandom    rdm;
10c4762a1bSJed Brown   PetscReal      enorm;
11c4762a1bSJed Brown   Vec            x,y,z,input,output;
12c4762a1bSJed Brown   Mat            A;
13c4762a1bSJed Brown   PetscInt       DIM, dim[5],vsize,row,col;
14c4762a1bSJed Brown   PetscReal      fac;
15c4762a1bSJed Brown 
16*9566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
17*9566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
18*9566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
19c4762a1bSJed Brown 
20c4762a1bSJed Brown #if defined(PETSC_USE_COMPLEX)
21c4762a1bSJed Brown   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "Example for Real DFT. Your current data type is complex!");
22c4762a1bSJed Brown #endif
23*9566063dSJacob Faibussowitsch   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rdm));
24*9566063dSJacob Faibussowitsch   PetscCall(PetscRandomSetFromOptions(rdm));
25*9566063dSJacob Faibussowitsch   PetscCall(VecCreate(PETSC_COMM_WORLD,&input));
26*9566063dSJacob Faibussowitsch   PetscCall(VecSetSizes(input,PETSC_DECIDE,N));
27*9566063dSJacob Faibussowitsch   PetscCall(VecSetFromOptions(input));
28*9566063dSJacob Faibussowitsch   PetscCall(VecSetRandom(input,rdm));
29*9566063dSJacob Faibussowitsch   PetscCall(VecDuplicate(input,&output));
30c4762a1bSJed Brown 
31c4762a1bSJed Brown   DIM  = 2; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4;
32*9566063dSJacob Faibussowitsch   PetscCall(MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A));
33*9566063dSJacob Faibussowitsch   PetscCall(MatGetLocalSize(A,&row,&col));
34c4762a1bSJed Brown   printf("The Matrix size  is %d and %d from process %d\n",row,col,rank);
35*9566063dSJacob Faibussowitsch   PetscCall(MatCreateVecsFFTW(A,&x,&y,&z));
36c4762a1bSJed Brown 
37*9566063dSJacob Faibussowitsch   PetscCall(VecGetSize(x,&vsize));
38c4762a1bSJed Brown 
39*9566063dSJacob Faibussowitsch   PetscCall(VecGetSize(z,&vsize));
40c4762a1bSJed Brown   printf("The vector size of output from the main routine is %d\n",vsize);
41c4762a1bSJed Brown 
42*9566063dSJacob Faibussowitsch   PetscCall(VecScatterPetscToFFTW(A,input,x));
43*9566063dSJacob Faibussowitsch   /*PetscCall(VecDestroy(&input));*/
44*9566063dSJacob Faibussowitsch   PetscCall(MatMult(A,x,y));
45*9566063dSJacob Faibussowitsch   PetscCall(MatMultTranspose(A,y,z));
46*9566063dSJacob Faibussowitsch   PetscCall(VecScatterFFTWToPetsc(A,z,output));
47*9566063dSJacob Faibussowitsch   /*PetscCall(VecDestroy(&z));*/
48c4762a1bSJed Brown   fac  = 1.0/(PetscReal)N;
49*9566063dSJacob Faibussowitsch   PetscCall(VecScale(output,fac));
50c4762a1bSJed Brown 
51*9566063dSJacob Faibussowitsch   PetscCall(VecAssemblyBegin(input));
52*9566063dSJacob Faibussowitsch   PetscCall(VecAssemblyEnd(input));
53*9566063dSJacob Faibussowitsch   PetscCall(VecAssemblyBegin(output));
54*9566063dSJacob Faibussowitsch   PetscCall(VecAssemblyEnd(output));
55c4762a1bSJed Brown 
56*9566063dSJacob Faibussowitsch /*  PetscCall(VecView(input,PETSC_VIEWER_STDOUT_WORLD));*/
57*9566063dSJacob Faibussowitsch /*  PetscCall(VecView(output,PETSC_VIEWER_STDOUT_WORLD));*/
58c4762a1bSJed Brown 
59*9566063dSJacob Faibussowitsch   PetscCall(VecAXPY(output,-1.0,input));
60*9566063dSJacob Faibussowitsch   PetscCall(VecNorm(output,NORM_1,&enorm));
61c4762a1bSJed Brown   if (enorm > 1.e-14) {
62*9566063dSJacob Faibussowitsch     PetscCall(PetscPrintf(PETSC_COMM_SELF,"  Error norm of |x - z| %e\n",enorm));
63c4762a1bSJed Brown   }
64c4762a1bSJed Brown 
65*9566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&x));
66*9566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&y));
67*9566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&z));
68*9566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&output));
69*9566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&input));
70*9566063dSJacob Faibussowitsch   PetscCall(MatDestroy(&A));
71*9566063dSJacob Faibussowitsch   PetscCall(PetscRandomDestroy(&rdm));
72*9566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
73b122ec5aSJacob Faibussowitsch   return 0;
74c4762a1bSJed Brown 
75c4762a1bSJed Brown }
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