1 2 static char help[] = "Saves 4by4 block matrix.\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat A; 9 PetscInt i,j; 10 PetscErrorCode ierr; 11 PetscMPIInt size; 12 PetscViewer fd; 13 PetscScalar values[16],one = 1.0; 14 Vec x; 15 16 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 17 ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr); 18 if (size > 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,m"Can only run on one processor"); 19 20 /* 21 Open binary file. Note that we use FILE_MODE_WRITE to indicate 22 writing to this file. 23 */ 24 ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"4by4",FILE_MODE_WRITE,&fd);CHKERRQ(ierr); 25 26 ierr = MatCreateSeqBAIJ(PETSC_COMM_WORLD,4,12,12,0,0,&A);CHKERRQ(ierr); 27 28 for (i=0; i<16; i++) values[i] = i; 29 for (i=0; i<4; i++) values[4*i+i] += 5; 30 i = 0; j = 0; 31 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 32 33 for (i=0; i<16; i++) values[i] = i; 34 i = 0; j = 2; 35 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 36 37 for (i=0; i<16; i++) values[i] = i; 38 i = 1; j = 0; 39 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 40 41 for (i=0; i<16; i++) values[i] = i;for (i=0; i<4; i++) values[4*i+i] += 6; 42 i = 1; j = 1; 43 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 44 45 for (i=0; i<16; i++) values[i] = i; 46 i = 2; j = 0; 47 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 48 49 for (i=0; i<16; i++) values[i] = i;for (i=0; i<4; i++) values[4*i+i] += 7; 50 i = 2; j = 2; 51 ierr = MatSetValuesBlocked(A,1,&i,1,&j,values,INSERT_VALUES);CHKERRQ(ierr); 52 53 ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 54 ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 55 ierr = MatView(A,fd);CHKERRQ(ierr); 56 ierr = MatDestroy(&A);CHKERRQ(ierr); 57 58 ierr = VecCreateSeq(PETSC_COMM_WORLD,12,&x);CHKERRQ(ierr); 59 ierr = VecSet(x,one);CHKERRQ(ierr); 60 ierr = VecView(x,fd);CHKERRQ(ierr); 61 ierr = VecDestroy(&x);CHKERRQ(ierr); 62 63 ierr = PetscViewerDestroy(&fd);CHKERRQ(ierr); 64 ierr = PetscFinalize(); 65 return ierr; 66 } 67