1 static char help[] = "Test MATMFFD for the rectangular case\n\n"; 2 3 #include <petscmat.h> 4 5 static PetscErrorCode myF(void* ctx,Vec x,Vec y) 6 { 7 const PetscScalar *ax; 8 PetscScalar *ay; 9 PetscInt i,j,m,n; 10 PetscErrorCode ierr; 11 12 PetscFunctionBegin; 13 ierr = VecGetArrayRead(x,&ax);CHKERRQ(ierr); 14 ierr = VecGetArray(y,&ay);CHKERRQ(ierr); 15 ierr = VecGetLocalSize(y,&m);CHKERRQ(ierr); 16 ierr = VecGetLocalSize(x,&n);CHKERRQ(ierr); 17 for (i=0;i<m;i++) { 18 PetscScalar xx,yy; 19 20 yy = 0.0; 21 for (j=0;j<n;j++) { 22 xx = PetscPowScalarInt(ax[j],i+1); 23 yy += xx; 24 } 25 ay[i] = yy; 26 } 27 ierr = VecRestoreArray(y,&ay);CHKERRQ(ierr); 28 ierr = VecRestoreArrayRead(x,&ax);CHKERRQ(ierr); 29 PetscFunctionReturn(0); 30 } 31 32 int main(int argc,char **args) 33 { 34 Mat A,B; 35 Vec base; 36 PetscInt m = 3 ,n = 2; 37 PetscErrorCode ierr; 38 39 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 40 ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr); 41 ierr = PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);CHKERRQ(ierr); 42 ierr = MatCreateMFFD(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,m,n,&A);CHKERRQ(ierr); 43 ierr = MatCreateVecs(A,&base,NULL);CHKERRQ(ierr); 44 ierr = VecSet(base,2.0);CHKERRQ(ierr); 45 ierr = MatMFFDSetFunction(A,myF,NULL);CHKERRQ(ierr); 46 ierr = MatMFFDSetBase(A,base,NULL);CHKERRQ(ierr); 47 ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 48 ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 49 ierr = MatComputeOperator(A,NULL,&B);CHKERRQ(ierr); 50 ierr = VecDestroy(&base);CHKERRQ(ierr); 51 ierr = MatDestroy(&A);CHKERRQ(ierr); 52 ierr = MatDestroy(&B);CHKERRQ(ierr); 53 ierr = PetscFinalize(); 54 return ierr; 55 } 56 57 /*TEST 58 59 test: 60 nsize: {{1 2 3 4}} 61 62 TEST*/ 63