1 2 static char help[] = "Tests automatic allocation of matrix storage space.\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C; 9 PetscInt i,j,m = 3,n = 3,Ii,J; 10 PetscErrorCode ierr; 11 PetscScalar v; 12 MatInfo info; 13 14 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 15 CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL)); 16 CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 17 18 /* create the matrix for the five point stencil, YET AGAIN */ 19 CHKERRQ(MatCreate(PETSC_COMM_SELF,&C)); 20 CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n)); 21 CHKERRQ(MatSetFromOptions(C)); 22 CHKERRQ(MatSetUp(C)); 23 for (i=0; i<m; i++) { 24 for (j=0; j<n; j++) { 25 v = -1.0; Ii = j + n*i; 26 if (i>0) {J=Ii-n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 27 if (i<m-1) {J=Ii+n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 28 if (j>0) {J=Ii-1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 29 if (j<n-1) {J=Ii+1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 30 v = 4.0; CHKERRQ(MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES)); 31 } 32 } 33 CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 34 CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 35 CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_SELF)); 36 37 CHKERRQ(MatGetInfo(C,MAT_LOCAL,&info)); 38 CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"matrix nonzeros = %" PetscInt_FMT ", allocated nonzeros = %" PetscInt_FMT "\n",(PetscInt)info.nz_used,(PetscInt)info.nz_allocated)); 39 40 CHKERRQ(MatDestroy(&C)); 41 ierr = PetscFinalize(); 42 return ierr; 43 } 44 45 /*TEST 46 47 test: 48 49 TEST*/ 50