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 ierr = PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);CHKERRQ(ierr); 16 ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr); 17 18 /* create the matrix for the five point stencil, YET AGAIN */ 19 ierr = MatCreate(PETSC_COMM_SELF,&C);CHKERRQ(ierr); 20 ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr); 21 ierr = MatSetFromOptions(C);CHKERRQ(ierr); 22 ierr = MatSetUp(C);CHKERRQ(ierr); 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; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 27 if (i<m-1) {J=Ii+n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 28 if (j>0) {J=Ii-1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 29 if (j<n-1) {J=Ii+1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} 30 v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr); 31 } 32 } 33 ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 34 ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 35 ierr = MatView(C,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 36 37 ierr = MatGetInfo(C,MAT_LOCAL,&info);CHKERRQ(ierr); 38 ierr = PetscPrintf(PETSC_COMM_SELF,"matrix nonzeros = %D, allocated nonzeros = %D\n",(PetscInt)info.nz_used,(PetscInt)info.nz_allocated);CHKERRQ(ierr); 39 40 ierr = MatDestroy(&C);CHKERRQ(ierr); 41 ierr = PetscFinalize(); 42 return ierr; 43 } 44 45 /*TEST 46 47 test: 48 49 TEST*/ 50