1 2 static char help[] = "Saves a dense matrix in a dense format (binary).\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C; 9 PetscScalar v; 10 PetscInt i,j,m = 4,n = 4; 11 PetscMPIInt rank,size; 12 PetscViewer viewer; 13 14 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 15 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 16 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 17 PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL)); 18 PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 19 20 /* PART 1: Generate matrix, then write it in binary format */ 21 22 /* Generate matrix */ 23 PetscCall(MatCreateSeqDense(PETSC_COMM_WORLD,m,n,NULL,&C)); 24 for (i=0; i<m; i++) { 25 for (j=0; j<n; j++) { 26 v = i*m+j; 27 PetscCall(MatSetValues(C,1,&i,1,&j,&v,INSERT_VALUES)); 28 } 29 } 30 PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 31 PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 32 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_WRITE,&viewer)); 33 PetscCall(MatView(C,viewer)); 34 PetscCall(PetscViewerDestroy(&viewer)); 35 PetscCall(MatDestroy(&C)); 36 PetscCall(PetscFinalize()); 37 return 0; 38 } 39 40 /*TEST 41 42 test: 43 44 TEST*/ 45