Actual source code: ex21.c
2: static char help[] = "Tests converting a parallel AIJ formatted matrix to the parallel Row format.\n\
3: This also tests MatGetRow() and MatRestoreRow() for the parallel case.\n\n";
5: #include <petscmat.h>
7: int main(int argc,char **args)
8: {
9: Mat C,A;
10: PetscInt i,j,m = 3,n = 2,Ii,J,rstart,rend,nz;
11: PetscMPIInt rank,size;
12: const PetscInt *idx;
13: PetscScalar v;
14: const PetscScalar *values;
16: PetscInitialize(&argc,&args,(char*)0,help);
17: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
18: MPI_Comm_size(PETSC_COMM_WORLD,&size);
19: n = 2*size;
21: /* create the matrix for the five point stencil, YET AGAIN*/
22: MatCreate(PETSC_COMM_WORLD,&C);
23: MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
24: MatSetFromOptions(C);
25: MatMPIAIJSetPreallocation(C,5,NULL,5,NULL);
26: MatSeqAIJSetPreallocation(C,5,NULL);
27: for (i=0; i<m; i++) {
28: for (j=2*rank; j<2*rank+2; j++) {
29: v = -1.0; Ii = j + n*i;
30: if (i>0) {J = Ii - n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
31: if (i<m-1) {J = Ii + n; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
32: if (j>0) {J = Ii - 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
33: if (j<n-1) {J = Ii + 1; MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);}
34: v = 4.0; MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);
35: }
36: }
37: MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);
38: MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);
39: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO);
40: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
41: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
42: MatView(C,PETSC_VIEWER_STDOUT_WORLD);
44: MatGetOwnershipRange(C,&rstart,&rend);
45: for (i=rstart; i<rend; i++) {
46: MatGetRow(C,i,&nz,&idx,&values);
47: PetscSynchronizedFPrintf(PETSC_COMM_WORLD,stdout,"[%d] get row %" PetscInt_FMT ": ",rank,i);
48: for (j=0; j<nz; j++) {
49: PetscSynchronizedFPrintf(PETSC_COMM_WORLD,stdout,"%" PetscInt_FMT " %g ",idx[j],(double)PetscRealPart(values[j]));
50: }
51: PetscSynchronizedFPrintf(PETSC_COMM_WORLD,stdout,"\n");
52: MatRestoreRow(C,i,&nz,&idx,&values);
53: }
54: PetscSynchronizedFlush(PETSC_COMM_WORLD,stdout);
56: MatConvert(C,MATSAME,MAT_INITIAL_MATRIX,&A);
57: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO);
58: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
59: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
60: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
62: MatDestroy(&A);
63: MatDestroy(&C);
64: PetscFinalize();
65: return 0;
66: }
68: /*TEST
70: test:
71: args: -mat_type seqaij
73: TEST*/