636 lines
38 KiB
C++
636 lines
38 KiB
C++
module;
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#include <algorithm>
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#include <array>
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#include <chrono>
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#include <cmath>
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#include <concepts>
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#include <cstdint>
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#include <limits>
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#include <memory>
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#include <optional>
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#include <stdexcept>
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#include <type_traits>
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#include <utility>
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#include <vector>
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#include <mfem.hpp>
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#include <mpi.h>
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export module mean_field:solver.coupled_trial_correction;
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export import :solver.linear_backend;
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export namespace mean_field::solver {
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struct FullCoupledStep final { };
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struct BacktrackedCoupledStep final {
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int maximumSteps{4};
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double reduction{.5};
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void Validate() const {
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if (maximumSteps <= 0 || !std::isfinite(reduction) || reduction <= 0.0 || reduction >= 1.0 ||
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std::pow(reduction, maximumSteps - 1) == 0.0)
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throw std::invalid_argument("Coupled damping requires positive resolved steps and a reduction strictly between zero and one.");
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}
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};
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struct EveryRejectedCoupledAttempt final { };
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struct NearAcceptanceCoupledAttempt final {
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double maximumExcessRatio{1.0};
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void Validate() const {
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if (!std::isfinite(maximumExcessRatio) || maximumExcessRatio <= 0.0)
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throw std::invalid_argument("A coupled prediction gate requires a finite positive excess ratio.");
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}
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};
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template <typename Candidate>
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concept CoupledCorrectionSearch = std::same_as<Candidate, FullCoupledStep> ||
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std::same_as<Candidate, BacktrackedCoupledStep>;
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template <typename Candidate>
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concept CoupledAttemptCriterion = std::same_as<Candidate, EveryRejectedCoupledAttempt> ||
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std::same_as<Candidate, NearAcceptanceCoupledAttempt>;
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struct CoupledTrialCorrectionOptions final {
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LinearSolveControl control{.relativeTolerance = .03, .absoluteTolerance = 1.e-14, .maximumIterations = 160};
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linear::FGMRESOptions backend{.restartLength = 160, .printLevel = -1};
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double maximumCorrectionRatio{1.0};
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void Validate() const {
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control.Validate();
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backend.Validate();
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if (control.relativeTolerance <= 0.0 || !std::isfinite(maximumCorrectionRatio) ||
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maximumCorrectionRatio <= 0.0)
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throw std::invalid_argument("Coupled trial correction requires positive relative tolerance and norm cap.");
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}
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};
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enum class CoupledTrialCorrectionStatus : std::uint8_t { admissible, linear_failure, norm_limit, non_finite };
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struct CoupledTrialCorrectionReport final {
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CoupledTrialCorrectionStatus status{CoupledTrialCorrectionStatus::linear_failure};
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LinearSolveReport linearSolve{};
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double verifiedTrueResidualNorm{std::numeric_limits<double>::quiet_NaN()};
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double convergenceThreshold{std::numeric_limits<double>::quiet_NaN()};
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double correctionNorm{std::numeric_limits<double>::quiet_NaN()};
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double maximumCorrectionNorm{std::numeric_limits<double>::quiet_NaN()};
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double verificationSeconds{0.0};
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bool verifiedGate{false};
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bool verificationApplied{false};
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[[nodiscard]] bool Admissible() const noexcept { return status == CoupledTrialCorrectionStatus::admissible; }
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};
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enum class CoupledTrialAttemptStatus : std::uint8_t {
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not_attempted, original_accepted, budget_exhausted, kept, linear_failure, norm_limit,
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non_finite, inadmissible, not_improved, prediction_deferred
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};
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enum class CoupledTrialCandidateStatus : std::uint8_t { evaluated, inadmissible, non_finite };
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struct CoupledTrialCandidateReport final {
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double beta{1.0};
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CoupledTrialCandidateStatus status{CoupledTrialCandidateStatus::inadmissible};
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double merit{std::numeric_limits<double>::quiet_NaN()};
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bool accepted{false};
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double preparationSeconds{0.0};
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};
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struct CoupledTrialDiagnostics final {
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std::uint64_t attempts{0}, kept{0}, fallbacks{0}, iterations{0}, preparations{0}, restorations{0};
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double solveSeconds{0.0}, verificationSeconds{0.0}, preparationSeconds{0.0}, refreshSeconds{0.0};
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// These fields describe the current trial; BeginTrial clears them even
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// when an earlier preparation rejection prevents another auxiliary solve.
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CoupledTrialAttemptStatus status{CoupledTrialAttemptStatus::not_attempted};
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std::optional<CoupledTrialCorrectionReport> currentSolve{};
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double originalMerit{std::numeric_limits<double>::quiet_NaN()};
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double correctedMerit{std::numeric_limits<double>::quiet_NaN()};
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std::uint64_t deferredAttempts{0};
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int candidateCount{0};
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double selectedBeta{std::numeric_limits<double>::quiet_NaN()};
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double baseMerit{std::numeric_limits<double>::quiet_NaN()};
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double linearPredictionMerit{std::numeric_limits<double>::quiet_NaN()};
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double predictedDecrease{std::numeric_limits<double>::quiet_NaN()};
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double predictionExcessRatio{std::numeric_limits<double>::quiet_NaN()};
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// Search candidates exclude the possible final replay of an earlier
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// best beta. Preparations/restorations still account for that work.
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std::vector<CoupledTrialCandidateReport> candidates{};
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};
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}
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namespace mean_field::solver::detail {
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template <typename Operation>
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concept CoupledGenerationAvailable = requires(const Operation &operation) {
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{ operation.GetPreparationGeneration() } -> std::convertible_to<std::uint64_t>;
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} || requires(const Operation &operation) {
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{ operation.GetProblem().GetPreparationGeneration() } -> std::convertible_to<std::uint64_t>;
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};
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template <CoupledGenerationAvailable Operation>
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std::uint64_t CoupledGeneration(const Operation &operation) {
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if constexpr (requires { operation.GetPreparationGeneration(); }) return operation.GetPreparationGeneration();
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else return operation.GetProblem().GetPreparationGeneration();
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}
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inline bool CoupledFinite(const mfem::Vector &values) {
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for (int index = 0; index < values.Size(); ++index)
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if (!std::isfinite(values(index))) return false;
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return true;
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}
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inline bool CoupledAll(bool condition, MPI_Comm communicator) {
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int local = condition, global = 0;
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if (MPI_Allreduce(&local, &global, 1, MPI_INT, MPI_MIN, communicator) != MPI_SUCCESS)
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throw std::runtime_error("A coupled trial correction could not reduce its validity check.");
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return global != 0;
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}
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inline double CoupledNorm(const mfem::Vector &values, MPI_Comm communicator) {
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const double local = values * values;
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double global = 0.0;
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if (MPI_Allreduce(&local, &global, 1, MPI_DOUBLE, MPI_SUM, communicator) != MPI_SUCCESS)
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throw std::runtime_error("A coupled trial correction could not reduce its norm.");
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return std::sqrt(global);
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}
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inline void CoupledRequire(bool condition, MPI_Comm communicator, const char *message) {
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if (!CoupledAll(condition, communicator)) throw std::invalid_argument(message);
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}
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inline CoupledTrialCorrectionOptions PrepareCoupledOptions(CoupledTrialCorrectionOptions options, MPI_Comm communicator) {
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int initialized = 0, finalized = 0;
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if (MPI_Initialized(&initialized) != MPI_SUCCESS || !initialized ||
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MPI_Finalized(&finalized) != MPI_SUCCESS || finalized)
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throw std::logic_error("A coupled trial correction requires initialized MPI that has not been finalized.");
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if (communicator == MPI_COMM_NULL) throw std::invalid_argument("A coupled trial correction requires a communicator.");
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bool valid = true;
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try { options.Validate(); } catch (const std::invalid_argument &) { valid = false; }
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CoupledRequire(valid, communicator, "Coupled trial correction controls are invalid on at least one rank.");
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const std::array<int, 3> integers{options.control.maximumIterations, options.backend.restartLength, options.backend.printLevel};
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const std::array<double, 3> reals{options.control.relativeTolerance, options.control.absoluteTolerance, options.maximumCorrectionRatio};
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std::array<int, 3> imin{}, imax{};
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std::array<double, 3> rmin{}, rmax{};
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if (MPI_Allreduce(integers.data(), imin.data(), 3, MPI_INT, MPI_MIN, communicator) != MPI_SUCCESS ||
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MPI_Allreduce(integers.data(), imax.data(), 3, MPI_INT, MPI_MAX, communicator) != MPI_SUCCESS ||
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MPI_Allreduce(reals.data(), rmin.data(), 3, MPI_DOUBLE, MPI_MIN, communicator) != MPI_SUCCESS ||
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MPI_Allreduce(reals.data(), rmax.data(), 3, MPI_DOUBLE, MPI_MAX, communicator) != MPI_SUCCESS)
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throw std::runtime_error("Coupled trial correction controls could not be compared across ranks.");
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if (imin != imax || rmin != rmax)
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throw std::invalid_argument("Coupled trial correction controls must agree across ranks.");
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return options;
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}
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template <typename Operation, typename Inverse>
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CoupledTrialCorrectionOptions PrepareCoupledSystemOptions(CoupledTrialCorrectionOptions options,
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const Operation &operation, const Inverse &inverse, MPI_Comm communicator) {
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options = PrepareCoupledOptions(options, communicator);
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CoupledRequire(operation.Height() >= 0 && operation.Width() == operation.Height() &&
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inverse.Height() == operation.Width() && inverse.Width() == operation.Height(), communicator,
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"A coupled correction requires compatible square operator and inverse dimensions.");
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const long long localSize = operation.Height();
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long long globalSize = 0;
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if (MPI_Allreduce(&localSize, &globalSize, 1, MPI_LONG_LONG, MPI_SUM, communicator) != MPI_SUCCESS)
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throw std::runtime_error("A coupled correction could not determine its global size.");
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if (globalSize == 0) throw std::invalid_argument("A coupled correction requires a globally nonempty system.");
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return options;
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}
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inline linear::FGMRES PrepareCoupledBackend(const CoupledTrialCorrectionOptions &options, MPI_Comm communicator) {
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return linear::FGMRES(PrepareCoupledOptions(options, communicator).backend);
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}
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}
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export namespace mean_field::solver {
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template <typename Operation>
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concept CoupledTrialOperation = std::derived_from<Operation, mfem::Operator> &&
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detail::CoupledGenerationAvailable<Operation> && requires(const Operation &operation) {
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{ operation.IsPrepared() } -> std::same_as<bool>;
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};
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template <typename Inverse>
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concept CoupledTrialInverse = std::derived_from<Inverse, mfem::Solver> && requires(const Inverse &inverse) {
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{ inverse.IsCurrent() } -> std::same_as<bool>;
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};
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// Capture fixes the affine target at the accepted linearization. Later
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// SolveCorrection borrows the freshly prepared candidate Jacobian; neither
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// operation owns or mutates a model state or the outer Newton direction.
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template <CoupledTrialOperation Operation, CoupledTrialInverse Inverse,
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LinearBackendConfiguration Backend = linear::FGMRES>
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requires LinearBackendRuntimeAvailableFor<Backend, Operation, Inverse>
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class PreparedCoupledTrialCorrection final {
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public:
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PreparedCoupledTrialCorrection(const Operation &operation, Inverse &inverse, MPI_Comm communicator,
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CoupledTrialCorrectionOptions options = {})
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requires std::same_as<Backend, linear::FGMRES>
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: PreparedCoupledTrialCorrection(operation, inverse, communicator, options,
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detail::PrepareCoupledBackend(options, communicator)) { }
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PreparedCoupledTrialCorrection(const Operation &operation, Inverse &inverse, MPI_Comm communicator,
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CoupledTrialCorrectionOptions options, Backend backend)
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: m_operation(std::addressof(operation)), m_inverse(std::addressof(inverse)), m_communicator(communicator),
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m_options(detail::PrepareCoupledSystemOptions(options, operation, inverse, communicator)),
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m_backend(prepareLinearBackend(std::move(backend), operation, inverse, communicator)),
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m_baseResidual(operation.Height()), m_baseAction(operation.Height()), m_rightHandSide(operation.Height()),
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m_verifiedAction(operation.Height()), m_defect(operation.Height()) {
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detail::CoupledRequire(IsCurrent(), communicator, "Coupled correction preparation requires a current operator and inverse.");
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}
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PreparedCoupledTrialCorrection(const PreparedCoupledTrialCorrection &) = delete;
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PreparedCoupledTrialCorrection &operator=(const PreparedCoupledTrialCorrection &) = delete;
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PreparedCoupledTrialCorrection(PreparedCoupledTrialCorrection &&) = delete;
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PreparedCoupledTrialCorrection &operator=(PreparedCoupledTrialCorrection &&) = delete;
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[[nodiscard]] bool IsCurrent() const {
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return m_operation->IsPrepared() && m_inverse->IsCurrent() && m_backend.IsReady() &&
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m_operation->Height() == m_operation->Width() &&
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m_inverse->Height() == m_operation->Width() && m_inverse->Width() == m_operation->Height() &&
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m_baseResidual.Size() == m_operation->Height() && m_baseAction.Size() == m_operation->Height();
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}
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[[nodiscard]] bool HasBase() const noexcept { return m_hasBase; }
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[[nodiscard]] std::uint64_t GetBaseGeneration() const noexcept { return m_baseGeneration; }
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[[nodiscard]] double GetBaseDirectionNorm() const noexcept { return m_directionNorm; }
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[[nodiscard]] MPI_Comm GetCommunicator() const noexcept { return m_communicator; }
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[[nodiscard]] const mfem::Vector &GetRightHandSide() const noexcept { return m_rightHandSide; }
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[[nodiscard]] const mfem::Vector &GetBaseResidual() const noexcept { return m_baseResidual; }
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[[nodiscard]] const mfem::Vector &GetVerifiedAction() const noexcept { return m_verifiedAction; }
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[[nodiscard]] const mfem::Vector &GetVerifiedDefect() const noexcept { return m_defect; }
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[[nodiscard]] const auto &GetLastReport() const noexcept { return m_lastReport; }
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[[nodiscard]] const CoupledTrialCorrectionOptions &GetOptions() const noexcept { return m_options; }
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void Invalidate() noexcept { m_hasBase = false; }
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void CaptureBase(const mfem::Vector &residual, const mfem::Vector &direction) {
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m_hasBase = false;
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detail::CoupledRequire(IsCurrent() && residual.Size() == m_operation->Height() &&
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direction.Size() == m_operation->Width() && detail::CoupledFinite(residual) && detail::CoupledFinite(direction),
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m_communicator, "Coupled correction capture requires a current base and finite compatible vectors.");
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m_baseResidual = residual;
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m_operation->Mult(direction, m_baseAction);
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m_directionNorm = detail::CoupledNorm(direction, m_communicator);
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detail::CoupledRequire(detail::CoupledFinite(m_baseAction) && std::isfinite(m_directionNorm), m_communicator,
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"The captured coupled correction tangent is nonfinite.");
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m_baseGeneration = detail::CoupledGeneration(*m_operation);
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m_hasBase = true;
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}
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void BuildLinearPrediction(double alpha, mfem::Vector &prediction) const {
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detail::CoupledRequire(m_hasBase && prediction.Size() == m_baseResidual.Size(), m_communicator,
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"A coupled prediction requires a captured base and compatible output.");
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RequireAlpha(alpha);
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prediction = m_baseResidual;
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prediction.Add(alpha, m_baseAction);
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detail::CoupledRequire(detail::CoupledFinite(prediction), m_communicator, "The coupled affine target is nonfinite.");
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}
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[[nodiscard]] CoupledTrialCorrectionReport SolveCorrection(double alpha, const mfem::Vector &trialResidual,
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mfem::Vector &correction) {
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detail::CoupledRequire(m_hasBase && IsCurrent() && detail::CoupledGeneration(*m_operation) >= m_baseGeneration &&
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trialResidual.Size() == m_operation->Height() && correction.Size() == m_operation->Width(),
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m_communicator, "Coupled correction requires a captured base, current candidate and compatible vectors.");
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RequireAlpha(alpha);
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CoupledTrialCorrectionReport report;
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const auto finish = [&]() { m_lastReport = report; return report; };
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correction = 0.0;
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m_verifiedAction = std::numeric_limits<double>::quiet_NaN();
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m_defect = std::numeric_limits<double>::quiet_NaN();
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report.maximumCorrectionNorm = m_options.maximumCorrectionRatio * alpha * m_directionNorm;
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BuildLinearPrediction(alpha, m_rightHandSide);
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m_rightHandSide -= trialResidual;
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if (!detail::CoupledAll(detail::CoupledFinite(m_rightHandSide) && std::isfinite(report.maximumCorrectionNorm), m_communicator)) {
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report.status = CoupledTrialCorrectionStatus::non_finite;
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return finish();
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}
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const double rhsNorm = detail::CoupledNorm(m_rightHandSide, m_communicator);
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const double relativeThreshold = m_options.control.relativeTolerance * rhsNorm;
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if (!std::isfinite(rhsNorm) || !std::isfinite(relativeThreshold)) {
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report.status = CoupledTrialCorrectionStatus::non_finite;
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return finish();
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}
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report.convergenceThreshold = m_options.control.ConvergenceThreshold(rhsNorm);
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report.linearSolve = m_backend.Solve(m_rightHandSide, correction, m_options.control);
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if (!detail::CoupledAll(correction.Size() == m_operation->Width() && detail::CoupledFinite(correction), m_communicator)) {
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report.status = CoupledTrialCorrectionStatus::non_finite;
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return finish();
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}
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const auto start = std::chrono::steady_clock::now();
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m_operation->Mult(correction, m_verifiedAction);
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report.verificationApplied = true;
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m_defect = m_verifiedAction;
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m_defect -= m_rightHandSide;
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const bool finite = detail::CoupledAll(detail::CoupledFinite(m_defect), m_communicator);
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report.verifiedTrueResidualNorm = finite ? detail::CoupledNorm(m_defect, m_communicator) :
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std::numeric_limits<double>::quiet_NaN();
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report.correctionNorm = detail::CoupledNorm(correction, m_communicator);
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report.verificationSeconds = std::chrono::duration<double>(std::chrono::steady_clock::now() - start).count();
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report.verifiedGate = std::isfinite(report.convergenceThreshold) && report.convergenceThreshold >= 0.0 &&
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std::isfinite(report.verifiedTrueResidualNorm) &&
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report.verifiedTrueResidualNorm <= report.convergenceThreshold;
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const bool solved = detail::CoupledAll(report.linearSolve.Converged(), m_communicator);
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if (!finite || !std::isfinite(report.verifiedTrueResidualNorm) || !std::isfinite(report.correctionNorm))
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report.status = CoupledTrialCorrectionStatus::non_finite;
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else if (!solved || !report.verifiedGate) report.status = CoupledTrialCorrectionStatus::linear_failure;
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else if (report.correctionNorm > report.maximumCorrectionNorm) report.status = CoupledTrialCorrectionStatus::norm_limit;
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else report.status = CoupledTrialCorrectionStatus::admissible;
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return finish();
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}
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private:
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void RequireAlpha(double alpha) const {
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detail::CoupledRequire(std::isfinite(alpha) && alpha >= 0.0, m_communicator,
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"Coupled correction requires a finite nonnegative step length.");
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double minimum = 0.0, maximum = 0.0;
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if (MPI_Allreduce(&alpha, &minimum, 1, MPI_DOUBLE, MPI_MIN, m_communicator) != MPI_SUCCESS ||
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MPI_Allreduce(&alpha, &maximum, 1, MPI_DOUBLE, MPI_MAX, m_communicator) != MPI_SUCCESS)
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throw std::runtime_error("A coupled correction could not compare step lengths.");
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if (minimum != maximum) throw std::invalid_argument("Coupled correction step lengths must agree across ranks.");
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}
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const Operation *m_operation;
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Inverse *m_inverse;
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MPI_Comm m_communicator;
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CoupledTrialCorrectionOptions m_options;
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PreparedLinearBackendType<Backend, Operation, Inverse> m_backend;
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mfem::Vector m_baseResidual, m_baseAction, m_rightHandSide, m_verifiedAction, m_defect;
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double m_directionNorm{0.0};
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std::uint64_t m_baseGeneration{0};
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bool m_hasBase{false};
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std::optional<CoupledTrialCorrectionReport> m_lastReport{};
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};
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}
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// The state protocol is deliberately structural: production and focused probes
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// execute the same transaction while their typed callbacks choose the metric
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// and enthalpy policy. This helper never reads or writes accepted-state buffers.
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export namespace mean_field::solver::detail {
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template <typename State, CoupledCorrectionSearch Search = FullCoupledStep,
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CoupledAttemptCriterion Attempt = EveryRejectedCoupledAttempt>
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class PreparedCoupledTrialTransaction final {
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using Operation = std::remove_cvref_t<decltype(*std::declval<State>().normalizedOperator)>;
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using Inverse = std::remove_cvref_t<decltype(*std::declval<State>().normalizedInverse)>;
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using Clock = std::chrono::steady_clock;
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public:
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PreparedCoupledTrialTransaction(State &state, const CoupledTrialCorrectionOptions &options,
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int maximumAttemptsPerIteration = 1, Search search = {}, Attempt attempt = {})
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: m_core(*state.normalizedOperator, *state.normalizedInverse, state.Problem().GetCommunicator(), options),
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m_maximumAttempts(maximumAttemptsPerIteration), m_search(search), m_attempt(attempt),
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m_originalState(state.normalizedOperator->Width()), m_originalResidual(state.normalizedOperator->Height()),
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m_originalPhysical(state.normalizedOperator->Width()), m_correction(state.normalizedOperator->Width()),
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m_selectedCorrection(state.normalizedOperator->Width()),
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m_prediction(std::same_as<Attempt, NearAcceptanceCoupledAttempt> ? state.normalizedOperator->Height() : 0) {
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ValidatePoliciesCollectively();
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m_selectedCorrection = 0.0;
|
|
m_diagnostics.candidates.reserve(MaximumSteps());
|
|
}
|
|
void CaptureBase(const mfem::Vector &residual, const mfem::Vector &direction) {
|
|
m_core.CaptureBase(residual, direction);
|
|
m_attemptsThisIteration = 0;
|
|
}
|
|
void BeginTrial() noexcept {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::not_attempted;
|
|
m_diagnostics.currentSolve.reset();
|
|
m_diagnostics.originalMerit = m_diagnostics.correctedMerit = m_diagnostics.selectedBeta =
|
|
m_diagnostics.baseMerit = m_diagnostics.linearPredictionMerit = m_diagnostics.predictedDecrease =
|
|
m_diagnostics.predictionExcessRatio = std::numeric_limits<double>::quiet_NaN();
|
|
m_diagnostics.candidateCount = 0;
|
|
m_diagnostics.candidates.clear();
|
|
m_selectedCorrection = 0.0;
|
|
}
|
|
[[nodiscard]] const CoupledTrialDiagnostics &GetDiagnostics() const noexcept { return m_diagnostics; }
|
|
[[nodiscard]] const auto &GetCore() const noexcept { return m_core; }
|
|
// The report verifies this unscaled vector. Damping changes the trial
|
|
// map, not the vector to which its original linear certificate applies.
|
|
[[nodiscard]] const mfem::Vector &GetCorrection() const noexcept { return m_correction; }
|
|
[[nodiscard]] const mfem::Vector &GetSelectedCorrection() const noexcept { return m_selectedCorrection; }
|
|
|
|
template <typename Preparation, typename Metric, typename Evaluate, typename Accepts, typename Better, typename CheckState>
|
|
void TryImprove(State &state, double alpha, Preparation &preparation, Metric &metric,
|
|
Evaluate &&evaluate, Accepts &&accepts, Better &&better, CheckState &&checkState) {
|
|
const auto communicator = m_core.GetCommunicator();
|
|
CoupledRequire(preparation.has_value() && state.normalizedOperator->IsPrepared() &&
|
|
CoupledFinite(state.trialNormalizedState) && CoupledFinite(state.trialNormalizedResidual) &&
|
|
ValidMetric(metric), communicator, "Coupled correction requires a successfully prepared original trial.");
|
|
m_diagnostics.originalMerit = metric.merit;
|
|
if (CoupledAll(accepts(metric), communicator)) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::original_accepted;
|
|
return;
|
|
}
|
|
if (m_attemptsThisIteration >= m_maximumAttempts) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::budget_exhausted;
|
|
return;
|
|
}
|
|
if constexpr (std::same_as<Attempt, NearAcceptanceCoupledAttempt>) {
|
|
// These are evaluations of saved residual vectors, not new
|
|
// physical candidates. No preparation, inverse refresh or
|
|
// attempt budget is spent on the prediction gate.
|
|
m_core.BuildLinearPrediction(alpha, m_prediction);
|
|
const auto baseMetric = evaluate(m_core.GetBaseResidual());
|
|
const auto predictionMetric = evaluate(m_prediction);
|
|
m_diagnostics.baseMerit = baseMetric.merit;
|
|
m_diagnostics.linearPredictionMerit = predictionMetric.merit;
|
|
m_diagnostics.predictedDecrease = baseMetric.merit - predictionMetric.merit;
|
|
const double decrease = m_diagnostics.predictedDecrease;
|
|
const double ratio = decrease > 0.0 ? (metric.merit - baseMetric.merit) / decrease :
|
|
std::numeric_limits<double>::quiet_NaN();
|
|
m_diagnostics.predictionExcessRatio = ratio;
|
|
if (!CoupledAll(ValidMetric(baseMetric) && ValidMetric(predictionMetric) && std::isfinite(decrease) &&
|
|
decrease > 0.0 && std::isfinite(ratio) && ratio <= m_attempt.maximumExcessRatio, communicator)) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::prediction_deferred;
|
|
++m_diagnostics.deferredAttempts;
|
|
return;
|
|
}
|
|
}
|
|
m_originalState = state.trialNormalizedState;
|
|
m_originalResidual = state.trialNormalizedResidual;
|
|
m_originalPhysical = state.candidatePhysicalState;
|
|
Refresh(state);
|
|
++m_attemptsThisIteration;
|
|
++m_diagnostics.attempts;
|
|
m_diagnostics.currentSolve = m_core.SolveCorrection(alpha, m_originalResidual, m_correction);
|
|
const auto &report = *m_diagnostics.currentSolve;
|
|
m_diagnostics.iterations += static_cast<std::uint64_t>(report.linearSolve.iterations);
|
|
m_diagnostics.solveSeconds += report.linearSolve.solveSeconds;
|
|
m_diagnostics.verificationSeconds += report.verificationSeconds;
|
|
if (!report.Admissible()) {
|
|
++m_diagnostics.fallbacks;
|
|
switch (report.status) {
|
|
case CoupledTrialCorrectionStatus::linear_failure: m_diagnostics.status = CoupledTrialAttemptStatus::linear_failure; break;
|
|
case CoupledTrialCorrectionStatus::norm_limit: m_diagnostics.status = CoupledTrialAttemptStatus::norm_limit; break;
|
|
default: m_diagnostics.status = CoupledTrialAttemptStatus::non_finite; break;
|
|
}
|
|
// No candidate mutation has occurred. In particular, a small
|
|
// beta cannot rescue an unverified or over-cap full correction.
|
|
return;
|
|
}
|
|
const Metric originalMetric = metric;
|
|
bool originalRestorationStarted = false;
|
|
auto restoreOriginal = [&]() {
|
|
originalRestorationStarted = true;
|
|
state.trialNormalizedState = m_originalState;
|
|
state.candidatePhysicalState = m_originalPhysical;
|
|
auto restored = Prepare(state);
|
|
++m_diagnostics.restorations;
|
|
if (!CoupledAll(restored.has_value() && CoupledFinite(state.trialNormalizedResidual), communicator))
|
|
throw std::runtime_error("A coupled trial fallback could not reprepare its original candidate.");
|
|
preparation = std::move(restored);
|
|
Refresh(state);
|
|
metric = evaluate(state.trialNormalizedResidual);
|
|
++m_diagnostics.fallbacks;
|
|
};
|
|
const auto formCandidate = [&](double beta) {
|
|
state.trialNormalizedState = m_originalState;
|
|
state.trialNormalizedState.Add(beta, m_correction);
|
|
state.normalizedOperator->DenormalizeState(state.trialNormalizedState, state.candidatePhysicalState);
|
|
};
|
|
try {
|
|
std::optional<Metric> bestMetric;
|
|
double bestBeta = 0.0;
|
|
int bestStep = -1, lastStep = -1;
|
|
double beta = 1.0;
|
|
for (int step = 0; step < MaximumSteps(); ++step, beta *= Reduction()) {
|
|
lastStep = step;
|
|
formCandidate(beta);
|
|
m_diagnostics.candidates.push_back({.beta = beta});
|
|
++m_diagnostics.candidateCount;
|
|
auto &candidate = m_diagnostics.candidates.back();
|
|
if (!CoupledAll(CoupledFinite(state.trialNormalizedState) && CoupledFinite(state.candidatePhysicalState), communicator)) {
|
|
candidate.status = CoupledTrialCandidateStatus::non_finite;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::non_finite;
|
|
continue;
|
|
}
|
|
if (!CoupledAll(checkState(state.trialNormalizedState), communicator)) {
|
|
candidate.status = CoupledTrialCandidateStatus::inadmissible;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::inadmissible;
|
|
continue;
|
|
}
|
|
const double preparationStart = m_diagnostics.preparationSeconds;
|
|
auto corrected = Prepare(state);
|
|
candidate.preparationSeconds = m_diagnostics.preparationSeconds - preparationStart;
|
|
if (!CoupledAll(corrected.has_value(), communicator)) {
|
|
candidate.status = CoupledTrialCandidateStatus::inadmissible;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::inadmissible;
|
|
continue;
|
|
}
|
|
if (!CoupledAll(CoupledFinite(state.trialNormalizedResidual), communicator)) {
|
|
candidate.status = CoupledTrialCandidateStatus::non_finite;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::non_finite;
|
|
continue;
|
|
}
|
|
const auto correctedMetric = evaluate(state.trialNormalizedResidual);
|
|
m_diagnostics.correctedMerit = correctedMetric.merit;
|
|
if (!CoupledAll(ValidMetric(correctedMetric), communicator)) {
|
|
candidate.status = CoupledTrialCandidateStatus::non_finite;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::non_finite;
|
|
continue;
|
|
}
|
|
preparation = std::move(corrected);
|
|
candidate.status = CoupledTrialCandidateStatus::evaluated;
|
|
candidate.merit = correctedMetric.merit;
|
|
const bool improves = CoupledAll(better(correctedMetric, originalMetric), communicator);
|
|
candidate.accepted = improves && CoupledAll(accepts(correctedMetric), communicator);
|
|
if (improves && (!bestMetric || candidate.accepted || CoupledAll(better(correctedMetric, *bestMetric), communicator))) {
|
|
bestMetric = correctedMetric;
|
|
bestBeta = beta;
|
|
bestStep = step;
|
|
}
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::not_improved;
|
|
// An improved but unacceptable full correction must not
|
|
// suppress the remaining, cheaper physical preparations.
|
|
if (candidate.accepted) break;
|
|
}
|
|
if (!bestMetric) {
|
|
restoreOriginal();
|
|
return;
|
|
}
|
|
if (bestStep != lastStep) {
|
|
// The current prepared operator belongs to the last beta,
|
|
// which can even be inadmissible. Replaying the selected
|
|
// state restores its residual, geometry and generation.
|
|
formCandidate(bestBeta);
|
|
if (!CoupledAll(checkState(state.trialNormalizedState), communicator)) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::inadmissible;
|
|
restoreOriginal();
|
|
return;
|
|
}
|
|
auto restored = Prepare(state);
|
|
++m_diagnostics.restorations;
|
|
if (!CoupledAll(restored.has_value() && CoupledFinite(state.trialNormalizedResidual), communicator)) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::inadmissible;
|
|
restoreOriginal();
|
|
return;
|
|
}
|
|
const auto restoredMetric = evaluate(state.trialNormalizedResidual);
|
|
if (!CoupledAll(ValidMetric(restoredMetric), communicator) ||
|
|
!CoupledAll(better(restoredMetric, originalMetric), communicator)) {
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::not_improved;
|
|
restoreOriginal();
|
|
return;
|
|
}
|
|
preparation = std::move(restored);
|
|
bestMetric = restoredMetric;
|
|
Refresh(state);
|
|
}
|
|
metric = *bestMetric;
|
|
m_selectedCorrection = m_correction;
|
|
m_selectedCorrection *= bestBeta;
|
|
m_diagnostics.selectedBeta = bestBeta;
|
|
m_diagnostics.correctedMerit = metric.merit;
|
|
m_diagnostics.status = CoupledTrialAttemptStatus::kept;
|
|
++m_diagnostics.kept;
|
|
// A current selected trial retains the ordinary lifecycle:
|
|
// its inverse is refreshed only on commit or another solve.
|
|
} catch (...) {
|
|
// Only collectively propagated callback exceptions can be
|
|
// rolled back collectively. Failure to restore propagates to
|
|
// the owning Newton context's accepted-base restoration.
|
|
if (!originalRestorationStarted) restoreOriginal();
|
|
throw;
|
|
}
|
|
}
|
|
|
|
private:
|
|
template <typename Metric> static bool ValidMetric(const Metric &metric) {
|
|
bool valid = std::isfinite(metric.merit) && metric.merit >= 0.0;
|
|
if constexpr (requires { metric.residualNorm; })
|
|
valid = valid && std::isfinite(metric.residualNorm) && metric.residualNorm >= 0.0;
|
|
return valid;
|
|
}
|
|
[[nodiscard]] int MaximumSteps() const noexcept {
|
|
if constexpr (std::same_as<Search, BacktrackedCoupledStep>) return m_search.maximumSteps;
|
|
else return 1;
|
|
}
|
|
[[nodiscard]] double Reduction() const noexcept {
|
|
if constexpr (std::same_as<Search, BacktrackedCoupledStep>) return m_search.reduction;
|
|
else return 1.0;
|
|
}
|
|
void ValidatePoliciesCollectively() const {
|
|
const auto communicator = m_core.GetCommunicator();
|
|
bool valid = m_maximumAttempts > 0;
|
|
try {
|
|
if constexpr (std::same_as<Search, BacktrackedCoupledStep>) m_search.Validate();
|
|
if constexpr (std::same_as<Attempt, NearAcceptanceCoupledAttempt>) m_attempt.Validate();
|
|
} catch (const std::invalid_argument &) { valid = false; }
|
|
CoupledRequire(valid, communicator, "Coupled trial search or attempt controls are invalid on at least one rank.");
|
|
double excessRatio = 0.0;
|
|
if constexpr (std::same_as<Attempt, NearAcceptanceCoupledAttempt>) excessRatio = m_attempt.maximumExcessRatio;
|
|
const std::array<int, 4> integers{m_maximumAttempts, std::same_as<Search, BacktrackedCoupledStep>,
|
|
MaximumSteps(), std::same_as<Attempt, NearAcceptanceCoupledAttempt>};
|
|
const std::array<double, 2> reals{Reduction(), excessRatio};
|
|
std::array<int, 4> minimumIntegers{}, maximumIntegers{};
|
|
std::array<double, 2> minimumReals{}, maximumReals{};
|
|
if (MPI_Allreduce(integers.data(), minimumIntegers.data(), 4, MPI_INT, MPI_MIN, communicator) != MPI_SUCCESS ||
|
|
MPI_Allreduce(integers.data(), maximumIntegers.data(), 4, MPI_INT, MPI_MAX, communicator) != MPI_SUCCESS ||
|
|
MPI_Allreduce(reals.data(), minimumReals.data(), 2, MPI_DOUBLE, MPI_MIN, communicator) != MPI_SUCCESS ||
|
|
MPI_Allreduce(reals.data(), maximumReals.data(), 2, MPI_DOUBLE, MPI_MAX, communicator) != MPI_SUCCESS)
|
|
throw std::runtime_error("Coupled trial search and attempt controls could not be compared.");
|
|
if (minimumIntegers != maximumIntegers || minimumReals != maximumReals)
|
|
throw std::invalid_argument("Coupled trial search and attempt controls must agree across ranks.");
|
|
}
|
|
void Refresh(State &state) {
|
|
const auto start = Clock::now();
|
|
state.physicalInverse->Refresh();
|
|
m_diagnostics.refreshSeconds += std::chrono::duration<double>(Clock::now() - start).count();
|
|
}
|
|
auto Prepare(State &state) {
|
|
const auto start = Clock::now();
|
|
auto result = state.PrepareTrial();
|
|
m_diagnostics.preparationSeconds += std::chrono::duration<double>(Clock::now() - start).count();
|
|
++m_diagnostics.preparations;
|
|
return result;
|
|
}
|
|
PreparedCoupledTrialCorrection<Operation, Inverse> m_core;
|
|
int m_maximumAttempts, m_attemptsThisIteration{0};
|
|
[[no_unique_address]] Search m_search;
|
|
[[no_unique_address]] Attempt m_attempt;
|
|
mfem::Vector m_originalState, m_originalResidual, m_originalPhysical, m_correction, m_selectedCorrection, m_prediction;
|
|
CoupledTrialDiagnostics m_diagnostics{};
|
|
};
|
|
}
|