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fix(PolytropeOperator): seperated boundary aware and unaware operators for M, Q, and D

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residual calculation needs to be done when boundary degrees of freedom have not been removed (since their removal takes place in the Mult step in order to introduce the proper restoring force). Whereas jacobian calculation needs to always work from the boundary aware operators (these are sparse matrices)

The other thing to note here is that this seems contrary to a matrix free design. While true it is common practive to assemble linear terms since they are cheap. We still never assemble the non linear matrix form.
This commit is contained in:
Emily Boudreaux
2025-05-22 11:30:24 -04:00
parent bd4aebedce
commit f5dea85db1
2 changed files with 53 additions and 41 deletions
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48
src/poly/utils/private/operator.cpp
View File

@@ -54,24 +54,34 @@ void PolytropeOperator::finalize(const mfem::Vector &initTheta) {
return;
}
m_M -> EliminateTestEssentialBC(m_theta_ess_tdofs.first);
m_M -> EliminateTrialEssentialBC(m_phi_ess_tdofs.first);
m_Mmat = std::make_unique<mfem::SparseMatrix>(m_M->SpMat());
m_Qmat = std::make_unique<mfem::SparseMatrix>(m_Q->SpMat());
m_Dmat = std::make_unique<mfem::SparseMatrix>(m_D->SpMat());
m_Q -> EliminateTestEssentialBC(m_phi_ess_tdofs.first);
m_Q -> EliminateTrialEssentialBC(m_theta_ess_tdofs.first);
// Remove the essential dofs from the constant matrices
for (const auto& dof: m_theta_ess_tdofs.first) {
m_Mmat->EliminateRow(dof);
m_Qmat->EliminateCol(dof);
}
m_D -> EliminateEssentialBC(m_phi_ess_tdofs.first);
for (const auto& dof: m_phi_ess_tdofs.first) {
m_Mmat->EliminateCol(dof);
m_Qmat->EliminateRow(dof);
m_Dmat->EliminateRowCol(dof);
}
m_negM_op = std::make_unique<mfem::ScaledOperator>(m_M.get(), -1.0);
m_negQ_op = std::make_unique<mfem::ScaledOperator>(m_Q.get(), -1.0);
m_negM_mat = std::make_unique<mfem::ScaledOperator>(m_Mmat.get(), -1.0);
m_negQ_mat = std::make_unique<mfem::ScaledOperator>(m_Qmat.get(), -1.0);
m_schurCompliment = std::make_unique<SchurCompliment>(*m_Q, *m_D, *m_M);
m_schurCompliment = std::make_unique<SchurCompliment>(*m_Qmat, *m_Dmat, *m_Mmat);
// Set up the constant parts of the jacobian now
// We use the assembled matrices with their boundary conditions already removed for the jacobian
m_jacobian = std::make_unique<mfem::BlockOperator>(m_blockOffsets);
m_jacobian->SetBlock(0, 1, m_negM_op.get()); //<- -M (constant)
m_jacobian->SetBlock(1, 0, m_negQ_op.get()); //<- -Q (constant)
m_jacobian->SetBlock(1, 1, m_D.get()); //<- D (constant)
m_jacobian->SetBlock(0, 1, m_negM_mat.get()); //<- -M (constant)
m_jacobian->SetBlock(1, 0, m_negQ_mat.get()); //<- -Q (constant)
m_jacobian->SetBlock(1, 1, m_Dmat.get()); //<- D (constant)
m_invSchurCompliment = std::make_unique<GMRESInverter>(*m_schurCompliment);
@@ -240,9 +250,9 @@ void GMRESInverter::Mult(const mfem::Vector &x, mfem::Vector &y) const {
SchurCompliment::SchurCompliment(
const mfem::MixedBilinearForm &QOp,
const mfem::BilinearForm &DOp,
const mfem::MixedBilinearForm &MOp,
const mfem::SparseMatrix &QOp,
const mfem::SparseMatrix &DOp,
const mfem::SparseMatrix &MOp,
const mfem::Solver &GradInvOp) :
mfem::Operator(DOp.Height(), DOp.Width())
{
@@ -252,9 +262,9 @@ mfem::Operator(DOp.Height(), DOp.Width())
}
SchurCompliment::SchurCompliment(
const mfem::MixedBilinearForm &QOp,
const mfem::BilinearForm &DOp,
const mfem::MixedBilinearForm &MOp) :
const mfem::SparseMatrix &QOp,
const mfem::SparseMatrix &DOp,
const mfem::SparseMatrix &MOp) :
mfem::Operator(DOp.Height(), DOp.Width())
{
updateConstantTerms(QOp, DOp, MOp);
@@ -262,7 +272,7 @@ mfem::Operator(DOp.Height(), DOp.Width())
m_nTheta = m_MOp->Height();
}
void SchurCompliment::SetOperator(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp, const mfem::Solver &GradInvOp) {
void SchurCompliment::SetOperator(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp, const mfem::Solver &GradInvOp) {
updateConstantTerms(QOp, DOp, MOp);
updateInverseNonlinearJacobian(GradInvOp);
}
@@ -271,7 +281,7 @@ void SchurCompliment::updateInverseNonlinearJacobian(const mfem::Solver &gradInv
m_GradInvOp = &gradInv;
}
void SchurCompliment::updateConstantTerms(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp) {
void SchurCompliment::updateConstantTerms(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp) {
m_QOp = &QOp;
m_DOp = &DOp;
m_MOp = &MOp;

46
src/poly/utils/public/operator.h
View File

@@ -28,22 +28,23 @@
class SchurCompliment final : public mfem::Operator {
public:
SchurCompliment(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp, const mfem::Solver &GradInvOp);
SchurCompliment(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp);
SchurCompliment(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp, const mfem::Solver &GradInvOp);
SchurCompliment(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp);
~SchurCompliment() override = default;
void Mult(const mfem::Vector &x, mfem::Vector &y) const override;
void SetOperator(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp, const mfem::Solver &GradInvOp);
void SetOperator(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp, const mfem::Solver &
GradInvOp);
void updateInverseNonlinearJacobian(const mfem::Solver &gradInv);
private:
void updateConstantTerms(const mfem::MixedBilinearForm &QOp, const mfem::BilinearForm &DOp, const mfem::MixedBilinearForm &MOp);
void updateConstantTerms(const mfem::SparseMatrix &QOp, const mfem::SparseMatrix &DOp, const mfem::SparseMatrix &MOp);
private:
// Note that these are not owned by this class
const mfem::MixedBilinearForm* m_QOp = nullptr;
const mfem::BilinearForm* m_DOp = nullptr;
const mfem::MixedBilinearForm* m_MOp = nullptr;
const mfem::SparseMatrix* m_QOp = nullptr;
const mfem::SparseMatrix* m_DOp = nullptr;
const mfem::SparseMatrix* m_MOp = nullptr;
const mfem::Solver* m_GradInvOp = nullptr;
int m_nPhi = 0;
int m_nTheta = 0;
@@ -101,32 +102,33 @@ private:
std::unique_ptr<mfem::BilinearForm> m_D;
std::unique_ptr<mfem::NonlinearForm> m_f;
// These are used to store the matrix representations
// for the bi-linear forms. This might seem counterintuitive
// for a matrix-free approach. However, these will be computed
// regardless due to MFEM's implementation of these operators.
// Further since these do not change it is not a performance issue.
// We need to store these separately because the jacobian and preconditioner
// must be computed from the boundary aware operators (which will be these
// matrices) whereas the residuals must be computed from the raw, physical,
// operators
std::unique_ptr<mfem::SparseMatrix> m_Mmat;
std::unique_ptr<mfem::SparseMatrix> m_Qmat;
std::unique_ptr<mfem::SparseMatrix> m_Dmat;
const mfem::Array<int> m_blockOffsets;
SSE::MFEMArrayPair m_theta_ess_tdofs;
SSE::MFEMArrayPair m_phi_ess_tdofs;
// std::unique_ptr<mfem::SparseMatrix> m_Mmat, m_Qmat, m_Dmat;
std::unique_ptr<mfem::ScaledOperator> m_negM_op;
std::unique_ptr<mfem::ScaledOperator> m_negQ_op;
std::unique_ptr<mfem::ScaledOperator> m_negM_mat;
std::unique_ptr<mfem::ScaledOperator> m_negQ_mat;
mutable std::unique_ptr<mfem::BlockOperator> m_jacobian;
// mutable std::unique_ptr<mfem::SparseMatrix> m_invSchurCompliment;
// mutable std::unique_ptr<mfem::SparseMatrix> m_invNonlinearJacobian;
mutable std::unique_ptr<SchurCompliment> m_schurCompliment;
mutable std::unique_ptr<GMRESInverter> m_invSchurCompliment;
mutable std::unique_ptr<mfem::Solver> m_invNonlinearJacobian;
/*
* The schur preconditioner has the form
*
* ⎡ḟ(θ)^-1 0 ⎤
* ⎣ 0 S^-1 ⎦
*
* Where S is the Schur compliment of the system
*
*/
mutable std::unique_ptr<mfem::BlockDiagonalPreconditioner> m_schurPreconditioner;
bool m_isFinalized = false;