1 2 static char help[] = "Tests MatCreateSubmatrix() with certain entire rows of matrix, modified from ex181.c."; 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,cstart,cend; 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 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 37 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 38 ierr = PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON);CHKERRQ(ierr); 39 ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 40 ierr = PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 41 42 /* 43 Generate a new matrix consisting every column of the original matrix 44 */ 45 ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr); 46 ierr = MatGetOwnershipRangeColumn(C,&cstart,&cend);CHKERRQ(ierr); 47 48 ierr = ISCreateStride(PETSC_COMM_WORLD,rend-rstart > 0 ? rend-rstart-1 : 0,rstart,1,&isrow);CHKERRQ(ierr); 49 ierr = ISCreateStride(PETSC_COMM_WORLD,cend-cstart,cstart,1,&iscol);CHKERRQ(ierr); 50 ierr = MatCreateSubMatrix(C,isrow,NULL,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr); 51 52 /* Change C to test the case MAT_REUSE_MATRIX */ 53 if (!rank ) { 54 i = 0; j = 0; v = 100; 55 ierr = MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES);CHKERRQ(ierr); 56 } 57 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 58 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 59 60 ierr = MatCreateSubMatrix(C,isrow,NULL,MAT_REUSE_MATRIX,&A);CHKERRQ(ierr); 61 ierr = PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON);CHKERRQ(ierr); 62 ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 63 ierr = PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 64 65 ierr = ISDestroy(&isrow);CHKERRQ(ierr); 66 ierr = ISDestroy(&iscol);CHKERRQ(ierr); 67 ierr = MatDestroy(&A);CHKERRQ(ierr); 68 ierr = MatDestroy(&C);CHKERRQ(ierr); 69 ierr = PetscFinalize(); 70 return ierr; 71 } 72 73 74 /*TEST 75 76 test: 77 nsize: 2 78 79 TEST*/ 80