1 2 static char help[] = "Tests MatCreateSubmatrix() in parallel."; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C,A; 9 PetscInt i,j,m = 3,n = 2,rstart,rend; 10 PetscMPIInt size,rank; 11 PetscErrorCode ierr; 12 PetscScalar v; 13 IS isrow,iscol; 14 15 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 16 ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); 17 ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr); 18 n = 2*size; 19 20 ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr); 21 ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr); 22 ierr = MatSetFromOptions(C);CHKERRQ(ierr); 23 ierr = MatSetUp(C);CHKERRQ(ierr); 24 25 /* 26 This is JUST to generate a nice test matrix, all processors fill up 27 the entire matrix. This is not something one would ever do in practice. 28 */ 29 ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr); 30 for (i=rstart; i<rend; i++) { 31 for (j=0; j<m*n; j++) { 32 v = i + j + 1; 33 ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); 34 } 35 } 36 37 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 38 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 39 ierr = PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON);CHKERRQ(ierr); 40 ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 41 42 /* 43 Generate a new matrix consisting of every second row and column of 44 the original matrix 45 */ 46 ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr); 47 /* Create parallel IS with the rows we want on THIS processor */ 48 ierr = ISCreateStride(PETSC_COMM_WORLD,(rend-rstart)/2,rstart,2,&isrow);CHKERRQ(ierr); 49 /* Create parallel IS with the rows we want on THIS processor (same as rows for now) */ 50 ierr = ISCreateStride(PETSC_COMM_WORLD,(rend-rstart)/2,rstart,2,&iscol);CHKERRQ(ierr); 51 52 ierr = MatCreateSubMatrix(C,isrow,iscol,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr); 53 ierr = MatCreateSubMatrix(C,isrow,iscol,MAT_REUSE_MATRIX,&A);CHKERRQ(ierr); 54 ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 55 56 ierr = ISDestroy(&isrow);CHKERRQ(ierr); 57 ierr = ISDestroy(&iscol);CHKERRQ(ierr); 58 ierr = MatDestroy(&A);CHKERRQ(ierr); 59 ierr = MatDestroy(&C);CHKERRQ(ierr); 60 ierr = PetscFinalize(); 61 return ierr; 62 } 63 64 65 /*TEST 66 67 test: 68 69 test: 70 suffix: 2 71 nsize: 3 72 73 test: 74 suffix: 2_baij 75 nsize: 3 76 args: -mat_type baij 77 78 test: 79 suffix: 2_sbaij 80 nsize: 3 81 args: -mat_type sbaij 82 83 test: 84 suffix: baij 85 args: -mat_type baij 86 output_file: output/ex59_1_baij.out 87 88 test: 89 suffix: sbaij 90 args: -mat_type sbaij 91 output_file: output/ex59_1_sbaij.out 92 93 TEST*/ 94