xref: /petsc/src/mat/tests/ex157.c (revision ad0e0ea304bf4da9652c37aefec3cf21b1ef8ffc)
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>
4*ad0e0ea3SStefano Zampini int main(int argc,char **args)
5c4762a1bSJed Brown {
6c4762a1bSJed Brown   PetscErrorCode ierr;
7c4762a1bSJed Brown   PetscMPIInt    rank,size;
8c4762a1bSJed Brown   PetscInt       N0=2048,N1=2048,N2=3,N3=5,N4=5,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;
14c4762a1bSJed Brown   PetscReal      fac;
15c4762a1bSJed Brown   PetscScalar    one=1,two=2,three=3;
16c4762a1bSJed Brown 
17c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
18c4762a1bSJed Brown #if defined(PETSC_USE_COMPLEX)
19c4762a1bSJed Brown   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP, "This example requires real numbers");
20c4762a1bSJed Brown #endif
21c4762a1bSJed Brown   ierr = MPI_Comm_size(PETSC_COMM_WORLD, &size);CHKERRQ(ierr);
22c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &rank);CHKERRQ(ierr);
23c4762a1bSJed Brown 
24c4762a1bSJed Brown   ierr = PetscRandomCreate(PETSC_COMM_WORLD, &rdm);CHKERRQ(ierr);
25c4762a1bSJed Brown   ierr = PetscRandomSetFromOptions(rdm);CHKERRQ(ierr);
26c4762a1bSJed Brown   ierr = VecCreate(PETSC_COMM_WORLD,&input);CHKERRQ(ierr);
27c4762a1bSJed Brown   ierr = VecSetSizes(input,PETSC_DECIDE,N);CHKERRQ(ierr);
28c4762a1bSJed Brown   ierr = VecSetFromOptions(input);CHKERRQ(ierr);
29c4762a1bSJed Brown /*  ierr = VecSet(input,one);CHKERRQ(ierr); */
30c4762a1bSJed Brown /*  ierr = VecSetValue(input,1,two,INSERT_VALUES);CHKERRQ(ierr); */
31c4762a1bSJed Brown /*  ierr = VecSetValue(input,2,three,INSERT_VALUES);CHKERRQ(ierr); */
32c4762a1bSJed Brown /*  ierr = VecSetValue(input,3,three,INSERT_VALUES);CHKERRQ(ierr); */
33c4762a1bSJed Brown   ierr = VecSetRandom(input,rdm);CHKERRQ(ierr);
34c4762a1bSJed Brown /*  ierr = VecSetRandom(input,rdm);CHKERRQ(ierr); */
35c4762a1bSJed Brown /*  ierr = VecSetRandom(input,rdm);CHKERRQ(ierr); */
36c4762a1bSJed Brown   ierr = VecDuplicate(input,&output);
37c4762a1bSJed Brown 
38c4762a1bSJed Brown   DIM  = 2; dim[0] = N0; dim[1] = N1; dim[2] = N2; dim[3] = N3; dim[4] = N4;
39c4762a1bSJed Brown   ierr = MatCreateFFT(PETSC_COMM_WORLD,DIM,dim,MATFFTW,&A);CHKERRQ(ierr);
40c4762a1bSJed Brown   ierr = MatCreateVecsFFTW(A,&x,&y,&z);CHKERRQ(ierr);
41c4762a1bSJed Brown /*  ierr = MatCreateVecs(A,&x,&y);CHKERRQ(ierr); */
42c4762a1bSJed Brown /*  ierr = MatCreateVecs(A,&z,NULL);CHKERRQ(ierr); */
43c4762a1bSJed Brown 
44c4762a1bSJed Brown   ierr = VecGetSize(x,&vsize);CHKERRQ(ierr);
45c4762a1bSJed Brown   printf("The vector size  of input from the main routine is %d\n",vsize);
46c4762a1bSJed Brown 
47c4762a1bSJed Brown   ierr = VecGetSize(z,&vsize);CHKERRQ(ierr);
48c4762a1bSJed Brown   printf("The vector size of output from the main routine is %d\n",vsize);
49c4762a1bSJed Brown 
50c4762a1bSJed Brown   ierr = InputTransformFFT(A,input,x);CHKERRQ(ierr);
51c4762a1bSJed Brown 
52c4762a1bSJed Brown   ierr = MatMult(A,x,y);CHKERRQ(ierr);
53c4762a1bSJed Brown   ierr = VecAssemblyBegin(y);CHKERRQ(ierr);
54c4762a1bSJed Brown   ierr = VecAssemblyEnd(y);CHKERRQ(ierr);
55c4762a1bSJed Brown   ierr = VecView(y,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
56c4762a1bSJed Brown 
57c4762a1bSJed Brown   ierr = MatMultTranspose(A,y,z);CHKERRQ(ierr);
58c4762a1bSJed Brown 
59c4762a1bSJed Brown   ierr = OutputTransformFFT(A,z,output);CHKERRQ(ierr);
60c4762a1bSJed Brown   fac  = 1.0/(PetscReal)N;
61c4762a1bSJed Brown   ierr = VecScale(output,fac);CHKERRQ(ierr);
62c4762a1bSJed Brown 
63c4762a1bSJed Brown   ierr = VecAssemblyBegin(input);CHKERRQ(ierr);
64c4762a1bSJed Brown   ierr = VecAssemblyEnd(input);CHKERRQ(ierr);
65c4762a1bSJed Brown   ierr = VecAssemblyBegin(output);CHKERRQ(ierr);
66c4762a1bSJed Brown   ierr = VecAssemblyEnd(output);CHKERRQ(ierr);
67c4762a1bSJed Brown 
68c4762a1bSJed Brown /*  ierr = VecView(input,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); */
69c4762a1bSJed Brown /*  ierr = VecView(output,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); */
70c4762a1bSJed Brown 
71c4762a1bSJed Brown   ierr = VecAXPY(output,-1.0,input);CHKERRQ(ierr);
72c4762a1bSJed Brown   ierr = VecNorm(output,NORM_1,&enorm);CHKERRQ(ierr);
73c4762a1bSJed Brown /*  if (enorm > 1.e-14) { */
74c4762a1bSJed Brown   ierr = PetscPrintf(PETSC_COMM_SELF,"  Error norm of |x - z| %e\n",enorm);CHKERRQ(ierr);
75c4762a1bSJed Brown /*      } */
76c4762a1bSJed Brown 
77c4762a1bSJed Brown   ierr = VecDestroy(&output);CHKERRQ(ierr);
78c4762a1bSJed Brown   ierr = VecDestroy(&input);CHKERRQ(ierr);
79c4762a1bSJed Brown   ierr = VecDestroy(&x);CHKERRQ(ierr);
80c4762a1bSJed Brown   ierr = VecDestroy(&y);CHKERRQ(ierr);
81c4762a1bSJed Brown   ierr = VecDestroy(&z);CHKERRQ(ierr);
82c4762a1bSJed Brown   ierr = MatDestroy(&A);CHKERRQ(ierr);
83c4762a1bSJed Brown   ierr = PetscRandomDestroy(&rdm);CHKERRQ(ierr);
84c4762a1bSJed Brown   ierr = PetscFinalize();
85c4762a1bSJed Brown   return ierr;
86c4762a1bSJed Brown 
87c4762a1bSJed Brown }
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