1 2 static char help[] = "Saves a rectangular sparse matrix to disk.\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat A; 9 PetscInt m = 100,n = 11,js[11],i,j,cnt; 10 PetscScalar values[11]; 11 PetscViewer view; 12 13 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 14 PetscCall(MatCreateSeqAIJ(PETSC_COMM_WORLD,m,n,20,0,&A)); 15 16 for (i=0; i<n; i++) values[i] = (PetscReal)i; 17 18 for (i=0; i<m; i++) { 19 cnt = 0; 20 if (i % 2) { 21 for (j=0; j<n; j += 2) { 22 js[cnt++] = j; 23 } 24 } else { 25 ; 26 } 27 PetscCall(MatSetValues(A,1,&i,cnt,js,values,INSERT_VALUES)); 28 } 29 PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY)); 30 PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY)); 31 32 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"rect",FILE_MODE_WRITE,&view)); 33 PetscCall(MatView(A,view)); 34 PetscCall(PetscViewerDestroy(&view)); 35 36 PetscCall(MatDestroy(&A)); 37 38 PetscCall(PetscFinalize()); 39 return 0; 40 } 41 42 /*TEST 43 44 test: 45 46 TEST*/ 47