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 PetscScalar v; 12 IS isrow,iscol; 13 14 CHKERRQ(PetscInitialize(&argc,&args,(char*)0,help)); 15 CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 16 CHKERRMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 17 n = 2*size; 18 19 CHKERRQ(MatCreate(PETSC_COMM_WORLD,&C)); 20 CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n)); 21 CHKERRQ(MatSetFromOptions(C)); 22 CHKERRQ(MatSetUp(C)); 23 24 /* 25 This is JUST to generate a nice test matrix, all processors fill up 26 the entire matrix. This is not something one would ever do in practice. 27 */ 28 CHKERRQ(MatGetOwnershipRange(C,&rstart,&rend)); 29 for (i=rstart; i<rend; i++) { 30 for (j=0; j<m*n; j++) { 31 v = i + j + 1; 32 CHKERRQ(MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES)); 33 } 34 } 35 CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 36 CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 37 CHKERRQ(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON)); 38 CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 39 CHKERRQ(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 40 41 /* 42 Generate a new matrix consisting every column of the original matrix 43 */ 44 CHKERRQ(MatGetOwnershipRange(C,&rstart,&rend)); 45 CHKERRQ(MatGetOwnershipRangeColumn(C,&cstart,&cend)); 46 47 CHKERRQ(ISCreateStride(PETSC_COMM_WORLD,rend-rstart > 0 ? rend-rstart-1 : 0,rstart,1,&isrow)); 48 CHKERRQ(ISCreateStride(PETSC_COMM_WORLD,cend-cstart,cstart,1,&iscol)); 49 CHKERRQ(MatCreateSubMatrix(C,isrow,NULL,MAT_INITIAL_MATRIX,&A)); 50 51 /* Change C to test the case MAT_REUSE_MATRIX */ 52 if (rank == 0) { 53 i = 0; j = 0; v = 100; 54 CHKERRQ(MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES)); 55 } 56 CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 57 CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 58 59 CHKERRQ(MatCreateSubMatrix(C,isrow,NULL,MAT_REUSE_MATRIX,&A)); 60 CHKERRQ(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_COMMON)); 61 CHKERRQ(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 62 CHKERRQ(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 63 64 CHKERRQ(ISDestroy(&isrow)); 65 CHKERRQ(ISDestroy(&iscol)); 66 CHKERRQ(MatDestroy(&A)); 67 CHKERRQ(MatDestroy(&C)); 68 CHKERRQ(PetscFinalize()); 69 return 0; 70 } 71 72 /*TEST 73 74 test: 75 nsize: 2 76 77 TEST*/ 78