1 2 static char help[] = "Tests sequential and parallel MatGetRow() and MatRestoreRow().\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C; 9 PetscInt i,j,m = 5,n = 5,Ii,J,nz,rstart,rend; 10 PetscErrorCode ierr; 11 PetscMPIInt rank; 12 const PetscInt *idx; 13 PetscScalar v; 14 const PetscScalar *values; 15 16 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 17 /* Create the matrix for the five point stencil, YET AGAIN */ 18 ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr); 19 ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr); 20 ierr = MatSetFromOptions(C);CHKERRQ(ierr); 21 ierr = MatSetUp(C);CHKERRQ(ierr); 22 for (i=0; i<m; i++) { 23 for (j=0; j<n; j++) { 24 v = -1.0; Ii = j + n*i; 25 if (i>0) {J = Ii - n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 26 if (i<m-1) {J = Ii + n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 27 if (j>0) {J = Ii - 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 28 if (j<n-1) {J = Ii + 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 29 v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr); 30 } 31 } 32 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 33 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 34 ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 35 36 ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); 37 ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr); 38 for (i=rstart; i<rend; i++) { 39 ierr = MatGetRow(C,i,&nz,&idx,&values);CHKERRQ(ierr); 40 if (!rank) { 41 for (j=0; j<nz; j++) { 42 ierr = PetscPrintf(PETSC_COMM_SELF,"%D %g ",idx[j],(double)PetscRealPart(values[j]));CHKERRQ(ierr); 43 } 44 ierr = PetscPrintf(PETSC_COMM_SELF,"\n");CHKERRQ(ierr); 45 } 46 ierr = MatRestoreRow(C,i,&nz,&idx,&values);CHKERRQ(ierr); 47 } 48 49 ierr = MatDestroy(&C);CHKERRQ(ierr); 50 ierr = PetscFinalize(); 51 return ierr; 52 } 53 54 55 /*TEST 56 57 test: 58 59 TEST*/ 60