PetscErrorCode MatDuplicate_IS(Mat mat,MatDuplicateOption op,Mat *newmat)
{
PetscErrorCode ierr;
Mat_IS *matis = (Mat_IS*)(mat->data);
PetscInt bs,m,n,M,N;
Mat B,localmat;
PetscFunctionBegin;
ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
ierr = MatGetSize(mat,&M,&N);CHKERRQ(ierr);
ierr = MatGetLocalSize(mat,&m,&n);CHKERRQ(ierr);
ierr = MatCreateIS(PetscObjectComm((PetscObject)mat),bs,m,n,M,N,matis->mapping,&B);CHKERRQ(ierr);
ierr = MatDuplicate(matis->A,op,&localmat);CHKERRQ(ierr);
ierr = MatISSetLocalMat(B,localmat);CHKERRQ(ierr);
ierr = MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
*newmat = B;
PetscFunctionReturn(0);
}
static PetscErrorCode ComputeMatrix(DomainData dd, Mat *A)
{
PetscErrorCode ierr;
GLLData gll;
Mat local_mat =0,temp_A=0;
ISLocalToGlobalMapping matis_map =0;
IS dirichletIS=0;
PetscFunctionBeginUser;
/* Compute some stuff of Gauss-Legendre-Lobatto quadrature rule */
ierr = GLLStuffs(dd,&gll);CHKERRQ(ierr);
/* Compute matrix of subdomain Neumann problem */
ierr = ComputeSubdomainMatrix(dd,gll,&local_mat);CHKERRQ(ierr);
/* Compute global mapping of local dofs */
ierr = ComputeMapping(dd,&matis_map);CHKERRQ(ierr);
/* Create MATIS object needed by BDDC */
ierr = MatCreateIS(dd.gcomm,1,PETSC_DECIDE,PETSC_DECIDE,dd.xm*dd.ym*dd.zm,dd.xm*dd.ym*dd.zm,matis_map,NULL,&temp_A);CHKERRQ(ierr);
/* Set local subdomain matrices into MATIS object */
ierr = MatScale(local_mat,dd.scalingfactor);CHKERRQ(ierr);
ierr = MatISSetLocalMat(temp_A,local_mat);CHKERRQ(ierr);
/* Call assembly functions */
ierr = MatAssemblyBegin(temp_A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(temp_A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
if (dd.DBC_zerorows) {
PetscInt dirsize;
ierr = ComputeSpecialBoundaryIndices(dd,&dirichletIS,NULL);CHKERRQ(ierr);
ierr = MatSetOption(local_mat,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE);CHKERRQ(ierr);
ierr = MatZeroRowsLocalIS(temp_A,dirichletIS,1.0,NULL,NULL);CHKERRQ(ierr);
ierr = ISGetLocalSize(dirichletIS,&dirsize);CHKERRQ(ierr);
/* giving hints to local and global matrices could be useful for the BDDC */
if (!dirsize) {
ierr = MatSetOption(local_mat,MAT_SYMMETRIC,PETSC_TRUE);CHKERRQ(ierr);
ierr = MatSetOption(local_mat,MAT_SPD,PETSC_TRUE);CHKERRQ(ierr);
} else {
ierr = MatSetOption(local_mat,MAT_SYMMETRIC,PETSC_FALSE);CHKERRQ(ierr);
ierr = MatSetOption(local_mat,MAT_SPD,PETSC_FALSE);CHKERRQ(ierr);
}
ierr = ISDestroy(&dirichletIS);CHKERRQ(ierr);
} else { /* safe to set the options for the global matrices (they will be communicated to the matis local matrices) */
ierr = MatSetOption(temp_A,MAT_SYMMETRIC,PETSC_TRUE);CHKERRQ(ierr);
ierr = MatSetOption(temp_A,MAT_SPD,PETSC_TRUE);CHKERRQ(ierr);
}
#if DEBUG
{
Vec lvec,rvec;
PetscReal norm;
ierr = MatCreateVecs(temp_A,&lvec,&rvec);CHKERRQ(ierr);
ierr = VecSet(lvec,1.0);CHKERRQ(ierr);
ierr = MatMult(temp_A,lvec,rvec);CHKERRQ(ierr);
ierr = VecNorm(rvec,NORM_INFINITY,&norm);CHKERRQ(ierr);
printf("Test null space of global mat % 1.14e\n",norm);
ierr = VecDestroy(&lvec);CHKERRQ(ierr);
ierr = VecDestroy(&rvec);CHKERRQ(ierr);
}
#endif
/* free allocated workspace */
ierr = PetscFree(gll.zGL);CHKERRQ(ierr);
ierr = PetscFree(gll.rhoGL);CHKERRQ(ierr);
ierr = PetscFree(gll.A[0]);CHKERRQ(ierr);
ierr = PetscFree(gll.A);CHKERRQ(ierr);
ierr = MatDestroy(&gll.elem_mat);CHKERRQ(ierr);
ierr = MatDestroy(&local_mat);CHKERRQ(ierr);
ierr = ISLocalToGlobalMappingDestroy(&matis_map);CHKERRQ(ierr);
/* give back the pointer to te MATIS object */
*A = temp_A;
PetscFunctionReturn(0);
}
