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mfem/linalg/operator.cpp
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2023-03-24 07:52:56 -07:00

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// Copyright (c) 2010-2023, Lawrence Livermore National Security, LLC. Produced
// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
// LICENSE and NOTICE for details. LLNL-CODE-806117.
//
// This file is part of the MFEM library. For more information and source code
// availability visit https://mfem.org.
//
// MFEM is free software; you can redistribute it and/or modify it under the
// terms of the BSD-3 license. We welcome feedback and contributions, see file
// CONTRIBUTING.md for details.
#include "vector.hpp"
#include "operator.hpp"
#include "../general/forall.hpp"
#include <iostream>
#include <iomanip>
namespace mfem
{
void Operator::InitTVectors(const Operator *Po, const Operator *Ri,
const Operator *Pi,
Vector &x, Vector &b,
Vector &X, Vector &B) const
{
if (!IsIdentityProlongation(Po))
{
// Variational restriction with Po
B.SetSize(Po->Width(), b);
Po->MultTranspose(b, B);
}
else
{
// B points to same data as b
B.MakeRef(b, 0, b.Size());
}
if (!IsIdentityProlongation(Pi))
{
// Variational restriction with Ri
X.SetSize(Ri->Height(), x);
Ri->Mult(x, X);
}
else
{
// X points to same data as x
X.MakeRef(x, 0, x.Size());
}
}
void Operator::AddMult(const Vector &x, Vector &y, const double a) const
{
mfem::Vector z(y.Size());
Mult(x, z);
y.Add(a, z);
}
void Operator::AddMultTranspose(const Vector &x, Vector &y,
const double a) const
{
mfem::Vector z(y.Size());
MultTranspose(x, z);
y.Add(a, z);
}
void Operator::ArrayMult(const Array<const Vector *> &X,
Array<Vector *> &Y) const
{
MFEM_ASSERT(X.Size() == Y.Size(),
"Number of columns mismatch in Operator::Mult!");
for (int i = 0; i < X.Size(); i++)
{
MFEM_ASSERT(X[i] && Y[i], "Missing Vector in Operator::Mult!");
Mult(*X[i], *Y[i]);
}
}
void Operator::ArrayMultTranspose(const Array<const Vector *> &X,
Array<Vector *> &Y) const
{
MFEM_ASSERT(X.Size() == Y.Size(),
"Number of columns mismatch in Operator::MultTranspose!");
for (int i = 0; i < X.Size(); i++)
{
MFEM_ASSERT(X[i] && Y[i], "Missing Vector in Operator::MultTranspose!");
MultTranspose(*X[i], *Y[i]);
}
}
void Operator::ArrayAddMult(const Array<const Vector *> &X, Array<Vector *> &Y,
const double a) const
{
MFEM_ASSERT(X.Size() == Y.Size(),
"Number of columns mismatch in Operator::AddMult!");
for (int i = 0; i < X.Size(); i++)
{
MFEM_ASSERT(X[i] && Y[i], "Missing Vector in Operator::AddMult!");
AddMult(*X[i], *Y[i], a);
}
}
void Operator::ArrayAddMultTranspose(const Array<const Vector *> &X,
Array<Vector *> &Y, const double a) const
{
MFEM_ASSERT(X.Size() == Y.Size(),
"Number of columns mismatch in Operator::AddMultTranspose!");
for (int i = 0; i < X.Size(); i++)
{
MFEM_ASSERT(X[i] && Y[i], "Missing Vector in Operator::AddMultTranspose!");
AddMultTranspose(*X[i], *Y[i], a);
}
}
void Operator::FormLinearSystem(const Array<int> &ess_tdof_list,
Vector &x, Vector &b,
Operator* &Aout, Vector &X, Vector &B,
int copy_interior)
{
const Operator *P = this->GetProlongation();
const Operator *R = this->GetRestriction();
InitTVectors(P, R, P, x, b, X, B);
if (!copy_interior) { X.SetSubVectorComplement(ess_tdof_list, 0.0); }
ConstrainedOperator *constrainedA;
FormConstrainedSystemOperator(ess_tdof_list, constrainedA);
constrainedA->EliminateRHS(X, B);
Aout = constrainedA;
}
void Operator::FormRectangularLinearSystem(
const Array<int> &trial_tdof_list,
const Array<int> &test_tdof_list, Vector &x, Vector &b,
Operator* &Aout, Vector &X, Vector &B)
{
const Operator *Pi = this->GetProlongation();
const Operator *Po = this->GetOutputProlongation();
const Operator *Ri = this->GetRestriction();
InitTVectors(Po, Ri, Pi, x, b, X, B);
RectangularConstrainedOperator *constrainedA;
FormRectangularConstrainedSystemOperator(trial_tdof_list, test_tdof_list,
constrainedA);
constrainedA->EliminateRHS(X, B);
Aout = constrainedA;
}
void Operator::RecoverFEMSolution(const Vector &X, const Vector &b, Vector &x)
{
// Same for Rectangular and Square operators
const Operator *P = this->GetProlongation();
if (!IsIdentityProlongation(P))
{
// Apply conforming prolongation
x.SetSize(P->Height());
P->Mult(X, x);
}
else
{
// X and x point to the same data
// If the validity flags of X's Memory were changed (e.g. if it was moved
// to device memory) then we need to tell x about that.
x.SyncMemory(X);
}
}
Operator * Operator::SetupRAP(const Operator *Pi, const Operator *Po)
{
Operator *rap;
if (!IsIdentityProlongation(Pi))
{
if (!IsIdentityProlongation(Po))
{
rap = new RAPOperator(*Po, *this, *Pi);
}
else
{
rap = new ProductOperator(this, Pi, false,false);
}
}
else
{
if (!IsIdentityProlongation(Po))
{
TransposeOperator * PoT = new TransposeOperator(Po);
rap = new ProductOperator(PoT, this, true,false);
}
else
{
rap = this;
}
}
return rap;
}
void Operator::FormConstrainedSystemOperator(
const Array<int> &ess_tdof_list, ConstrainedOperator* &Aout)
{
const Operator *P = this->GetProlongation();
Operator *rap = SetupRAP(P, P);
// Impose the boundary conditions through a ConstrainedOperator, which owns
// the rap operator when P and R are non-trivial
ConstrainedOperator *A = new ConstrainedOperator(rap, ess_tdof_list,
rap != this);
Aout = A;
}
void Operator::FormRectangularConstrainedSystemOperator(
const Array<int> &trial_tdof_list, const Array<int> &test_tdof_list,
RectangularConstrainedOperator* &Aout)
{
const Operator *Pi = this->GetProlongation();
const Operator *Po = this->GetOutputProlongation();
Operator *rap = SetupRAP(Pi, Po);
// Impose the boundary conditions through a RectangularConstrainedOperator,
// which owns the rap operator when P and R are non-trivial
RectangularConstrainedOperator *A
= new RectangularConstrainedOperator(rap,
trial_tdof_list, test_tdof_list,
rap != this);
Aout = A;
}
void Operator::FormSystemOperator(const Array<int> &ess_tdof_list,
Operator* &Aout)
{
ConstrainedOperator *A;
FormConstrainedSystemOperator(ess_tdof_list, A);
Aout = A;
}
void Operator::FormRectangularSystemOperator(const Array<int> &trial_tdof_list,
const Array<int> &test_tdof_list,
Operator* &Aout)
{
RectangularConstrainedOperator *A;
FormRectangularConstrainedSystemOperator(trial_tdof_list, test_tdof_list, A);
Aout = A;
}
void Operator::FormDiscreteOperator(Operator* &Aout)
{
const Operator *Pin = this->GetProlongation();
const Operator *Rout = this->GetOutputRestriction();
Aout = new TripleProductOperator(Rout, this, Pin,false, false, false);
}
void Operator::PrintMatlab(std::ostream & os, int n, int m) const
{
using namespace std;
if (n == 0) { n = width; }
if (m == 0) { m = height; }
Vector x(n), y(m);
x = 0.0;
os << setiosflags(ios::scientific | ios::showpos);
for (int i = 0; i < n; i++)
{
x(i) = 1.0;
Mult(x, y);
for (int j = 0; j < m; j++)
{
if (y(j) != 0)
{
os << j+1 << " " << i+1 << " " << y(j) << '\n';
}
}
x(i) = 0.0;
}
}
void Operator::PrintMatlab(std::ostream &os) const
{
PrintMatlab(os, width, height);
}
void TimeDependentOperator::ExplicitMult(const Vector &, Vector &) const
{
mfem_error("TimeDependentOperator::ExplicitMult() is not overridden!");
}
void TimeDependentOperator::ImplicitMult(const Vector &, const Vector &,
Vector &) const
{
mfem_error("TimeDependentOperator::ImplicitMult() is not overridden!");
}
void TimeDependentOperator::Mult(const Vector &, Vector &) const
{
mfem_error("TimeDependentOperator::Mult() is not overridden!");
}
void TimeDependentOperator::ImplicitSolve(const double, const Vector &,
Vector &)
{
mfem_error("TimeDependentOperator::ImplicitSolve() is not overridden!");
}
Operator &TimeDependentOperator::GetImplicitGradient(
const Vector &, const Vector &, double) const
{
mfem_error("TimeDependentOperator::GetImplicitGradient() is "
"not overridden!");
return const_cast<Operator &>(dynamic_cast<const Operator &>(*this));
}
Operator &TimeDependentOperator::GetExplicitGradient(const Vector &) const
{
mfem_error("TimeDependentOperator::GetExplicitGradient() is "
"not overridden!");
return const_cast<Operator &>(dynamic_cast<const Operator &>(*this));
}
int TimeDependentOperator::SUNImplicitSetup(const Vector &,
const Vector &,
int, int *, double)
{
mfem_error("TimeDependentOperator::SUNImplicitSetup() is not overridden!");
return (-1);
}
int TimeDependentOperator::SUNImplicitSolve(const Vector &, Vector &, double)
{
mfem_error("TimeDependentOperator::SUNImplicitSolve() is not overridden!");
return (-1);
}
int TimeDependentOperator::SUNMassSetup()
{
mfem_error("TimeDependentOperator::SUNMassSetup() is not overridden!");
return (-1);
}
int TimeDependentOperator::SUNMassSolve(const Vector &, Vector &, double)
{
mfem_error("TimeDependentOperator::SUNMassSolve() is not overridden!");
return (-1);
}
int TimeDependentOperator::SUNMassMult(const Vector &, Vector &)
{
mfem_error("TimeDependentOperator::SUNMassMult() is not overridden!");
return (-1);
}
void SecondOrderTimeDependentOperator::Mult(const Vector &x,
const Vector &dxdt,
Vector &y) const
{
mfem_error("SecondOrderTimeDependentOperator::Mult() is not overridden!");
}
void SecondOrderTimeDependentOperator::ImplicitSolve(const double dt0,
const double dt1,
const Vector &x,
const Vector &dxdt,
Vector &k)
{
mfem_error("SecondOrderTimeDependentOperator::ImplicitSolve() is not overridden!");
}
ProductOperator::ProductOperator(const Operator *A, const Operator *B,
bool ownA, bool ownB)
: Operator(A->Height(), B->Width()),
A(A), B(B), ownA(ownA), ownB(ownB), z(A->Width())
{
MFEM_VERIFY(A->Width() == B->Height(),
"incompatible Operators: A->Width() = " << A->Width()
<< ", B->Height() = " << B->Height());
{
const Solver* SolverB = dynamic_cast<const Solver*>(B);
if (SolverB)
{
MFEM_VERIFY(!(SolverB->iterative_mode),
"Operator B of a ProductOperator should not be in iterative mode");
}
}
}
ProductOperator::~ProductOperator()
{
if (ownA) { delete A; }
if (ownB) { delete B; }
}
RAPOperator::RAPOperator(const Operator &Rt_, const Operator &A_,
const Operator &P_)
: Operator(Rt_.Width(), P_.Width()), Rt(Rt_), A(A_), P(P_)
{
MFEM_VERIFY(Rt.Height() == A.Height(),
"incompatible Operators: Rt.Height() = " << Rt.Height()
<< ", A.Height() = " << A.Height());
MFEM_VERIFY(A.Width() == P.Height(),
"incompatible Operators: A.Width() = " << A.Width()
<< ", P.Height() = " << P.Height());
{
const Solver* SolverA = dynamic_cast<const Solver*>(&A);
if (SolverA)
{
MFEM_VERIFY(!(SolverA->iterative_mode),
"Operator A of an RAPOperator should not be in iterative mode");
}
const Solver* SolverP = dynamic_cast<const Solver*>(&P);
if (SolverP)
{
MFEM_VERIFY(!(SolverP->iterative_mode),
"Operator P of an RAPOperator should not be in iterative mode");
}
}
mem_class = Rt.GetMemoryClass()*P.GetMemoryClass();
MemoryType mem_type = GetMemoryType(A.GetMemoryClass()*mem_class);
Px.SetSize(P.Height(), mem_type);
APx.SetSize(A.Height(), mem_type);
}
TripleProductOperator::TripleProductOperator(
const Operator *A, const Operator *B, const Operator *C,
bool ownA, bool ownB, bool ownC)
: Operator(A->Height(), C->Width())
, A(A), B(B), C(C)
, ownA(ownA), ownB(ownB), ownC(ownC)
{
MFEM_VERIFY(A->Width() == B->Height(),
"incompatible Operators: A->Width() = " << A->Width()
<< ", B->Height() = " << B->Height());
MFEM_VERIFY(B->Width() == C->Height(),
"incompatible Operators: B->Width() = " << B->Width()
<< ", C->Height() = " << C->Height());
{
const Solver* SolverB = dynamic_cast<const Solver*>(B);
if (SolverB)
{
MFEM_VERIFY(!(SolverB->iterative_mode),
"Operator B of a TripleProductOperator should not be in iterative mode");
}
const Solver* SolverC = dynamic_cast<const Solver*>(C);
if (SolverC)
{
MFEM_VERIFY(!(SolverC->iterative_mode),
"Operator C of a TripleProductOperator should not be in iterative mode");
}
}
mem_class = A->GetMemoryClass()*C->GetMemoryClass();
MemoryType mem_type = GetMemoryType(mem_class*B->GetMemoryClass());
t1.SetSize(C->Height(), mem_type);
t2.SetSize(B->Height(), mem_type);
}
TripleProductOperator::~TripleProductOperator()
{
if (ownA) { delete A; }
if (ownB) { delete B; }
if (ownC) { delete C; }
}
ConstrainedOperator::ConstrainedOperator(Operator *A, const Array<int> &list,
bool own_A_,
DiagonalPolicy diag_policy_)
: Operator(A->Height(), A->Width()), A(A), own_A(own_A_),
diag_policy(diag_policy_)
{
// 'mem_class' should work with A->Mult() and mfem::forall():
mem_class = A->GetMemoryClass()*Device::GetDeviceMemoryClass();
MemoryType mem_type = GetMemoryType(mem_class);
list.Read(); // TODO: just ensure 'list' is registered, no need to copy it
constraint_list.MakeRef(list);
// typically z and w are large vectors, so store them on the device
z.SetSize(height, mem_type); z.UseDevice(true);
w.SetSize(height, mem_type); w.UseDevice(true);
}
void ConstrainedOperator::AssembleDiagonal(Vector &diag) const
{
A->AssembleDiagonal(diag);
if (diag_policy == DIAG_KEEP) { return; }
const int csz = constraint_list.Size();
auto d_diag = diag.ReadWrite();
auto idx = constraint_list.Read();
switch (diag_policy)
{
case DIAG_ONE:
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_diag[id] = 1.0;
});
break;
case DIAG_ZERO:
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_diag[id] = 0.0;
});
break;
default:
MFEM_ABORT("unknown diagonal policy");
break;
}
}
void ConstrainedOperator::EliminateRHS(const Vector &x, Vector &b) const
{
w = 0.0;
const int csz = constraint_list.Size();
auto idx = constraint_list.Read();
auto d_x = x.Read();
// Use read+write access - we are modifying sub-vector of w
auto d_w = w.ReadWrite();
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_w[id] = d_x[id];
});
// A.AddMult(w, b, -1.0); // if available to all Operators
A->Mult(w, z);
b -= z;
// Use read+write access - we are modifying sub-vector of b
auto d_b = b.ReadWrite();
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_b[id] = d_x[id];
});
}
void ConstrainedOperator::Mult(const Vector &x, Vector &y) const
{
const int csz = constraint_list.Size();
if (csz == 0)
{
A->Mult(x, y);
return;
}
z = x;
auto idx = constraint_list.Read();
// Use read+write access - we are modifying sub-vector of z
auto d_z = z.ReadWrite();
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i) { d_z[idx[i]] = 0.0; });
A->Mult(z, y);
auto d_x = x.Read();
// Use read+write access - we are modifying sub-vector of y
auto d_y = y.ReadWrite();
switch (diag_policy)
{
case DIAG_ONE:
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_y[id] = d_x[id];
});
break;
case DIAG_ZERO:
mfem::forall(csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = idx[i];
d_y[id] = 0.0;
});
break;
case DIAG_KEEP:
// Needs action of the operator diagonal on vector
mfem_error("ConstrainedOperator::Mult #1");
break;
default:
mfem_error("ConstrainedOperator::Mult #2");
break;
}
}
RectangularConstrainedOperator::RectangularConstrainedOperator(
Operator *A,
const Array<int> &trial_list,
const Array<int> &test_list,
bool own_A_)
: Operator(A->Height(), A->Width()), A(A), own_A(own_A_)
{
// 'mem_class' should work with A->Mult() and mfem::forall():
mem_class = A->GetMemoryClass()*Device::GetMemoryClass();
MemoryType mem_type = GetMemoryType(mem_class);
trial_list.Read(); // TODO: just ensure 'list' is registered, no need to copy it
test_list.Read(); // TODO: just ensure 'list' is registered, no need to copy it
trial_constraints.MakeRef(trial_list);
test_constraints.MakeRef(test_list);
// typically z and w are large vectors, so store them on the device
z.SetSize(height, mem_type); z.UseDevice(true);
w.SetSize(width, mem_type); w.UseDevice(true);
}
void RectangularConstrainedOperator::EliminateRHS(const Vector &x,
Vector &b) const
{
w = 0.0;
const int trial_csz = trial_constraints.Size();
auto trial_idx = trial_constraints.Read();
auto d_x = x.Read();
// Use read+write access - we are modifying sub-vector of w
auto d_w = w.ReadWrite();
mfem::forall(trial_csz, [=] MFEM_HOST_DEVICE (int i)
{
const int id = trial_idx[i];
d_w[id] = d_x[id];
});
// A.AddMult(w, b, -1.0); // if available to all Operators
A->Mult(w, z);
b -= z;
const int test_csz = test_constraints.Size();
auto test_idx = test_constraints.Read();
auto d_b = b.ReadWrite();
mfem::forall(test_csz, [=] MFEM_HOST_DEVICE (int i)
{
d_b[test_idx[i]] = 0.0;
});
}
void RectangularConstrainedOperator::Mult(const Vector &x, Vector &y) const
{
const int trial_csz = trial_constraints.Size();
const int test_csz = test_constraints.Size();
if (trial_csz == 0)
{
A->Mult(x, y);
}
else
{
w = x;
auto idx = trial_constraints.Read();
// Use read+write access - we are modifying sub-vector of w
auto d_w = w.ReadWrite();
mfem::forall(trial_csz, [=] MFEM_HOST_DEVICE (int i)
{
d_w[idx[i]] = 0.0;
});
A->Mult(w, y);
}
if (test_csz != 0)
{
auto idx = test_constraints.Read();
auto d_y = y.ReadWrite();
mfem::forall(test_csz, [=] MFEM_HOST_DEVICE (int i)
{
d_y[idx[i]] = 0.0;
});
}
}
void RectangularConstrainedOperator::MultTranspose(const Vector &x,
Vector &y) const
{
const int trial_csz = trial_constraints.Size();
const int test_csz = test_constraints.Size();
if (test_csz == 0)
{
A->MultTranspose(x, y);
}
else
{
z = x;
auto idx = test_constraints.Read();
// Use read+write access - we are modifying sub-vector of z
auto d_z = z.ReadWrite();
mfem::forall(test_csz, [=] MFEM_HOST_DEVICE (int i)
{
d_z[idx[i]] = 0.0;
});
A->MultTranspose(z, y);
}
if (trial_csz != 0)
{
auto idx = trial_constraints.Read();
auto d_y = y.ReadWrite();
mfem::forall(trial_csz, [=] MFEM_HOST_DEVICE (int i)
{
d_y[idx[i]] = 0.0;
});
}
}
double PowerMethod::EstimateLargestEigenvalue(Operator& opr, Vector& v0,
int numSteps, double tolerance, int seed)
{
v1.SetSize(v0.Size());
if (seed != 0)
{
v0.Randomize(seed);
}
double eigenvalue = 1.0;
for (int iter = 0; iter < numSteps; ++iter)
{
double normV0;
#ifdef MFEM_USE_MPI
if (comm != MPI_COMM_NULL)
{
normV0 = InnerProduct(comm, v0, v0);
}
else
{
normV0 = InnerProduct(v0, v0);
}
#else
normV0 = InnerProduct(v0, v0);
#endif
v0 /= sqrt(normV0);
opr.Mult(v0, v1);
double eigenvalueNew;
#ifdef MFEM_USE_MPI
if (comm != MPI_COMM_NULL)
{
eigenvalueNew = InnerProduct(comm, v0, v1);
}
else
{
eigenvalueNew = InnerProduct(v0, v1);
}
#else
eigenvalueNew = InnerProduct(v0, v1);
#endif
double diff = std::abs((eigenvalueNew - eigenvalue) / eigenvalue);
eigenvalue = eigenvalueNew;
std::swap(v0, v1);
if (diff < tolerance)
{
break;
}
}
return eigenvalue;
}
}