Add frozen polynomial positivity probes and tighten certificate diagnostics

This commit is contained in:
2026-09-17 09:31:31 -04:00
parent dfba40b1f5
commit 97204a3253
3 changed files with 213 additions and 2 deletions

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@@ -0,0 +1,187 @@
#pragma once
#include <array>
#include <chrono>
#include <exception>
#include <filesystem>
#include <fstream>
#include <iomanip>
#include <limits>
#include <span>
#include <stdexcept>
#include <string>
#include <type_traits>
#include <vector>
// Include after import mean_field. Frozen probes never substitute their base
// into accepted buffers: the context's original seed supplies the safe anchor.
namespace experiment::plateau_diagnostics {
namespace polynomial_probe_detail {
inline const char *Status(mean_field::solver::PolynomialSignStatus status) {
using S = mean_field::solver::PolynomialSignStatus;
switch (status) {
case S::certified_nonnegative: return "certified_nonnegative";
case S::unresolved: return "unresolved";
case S::negative: return "negative";
case S::non_finite: return "non_finite";
}
return "unknown";
}
inline const char *RepairStatus(mean_field::solver::EnthalpyDirectionRepairStatus status) {
using S = mean_field::solver::EnthalpyDirectionRepairStatus;
switch (status) {
case S::feasible: return "feasible";
case S::invalid_base: return "invalid_base";
case S::invalid_anchor: return "invalid_anchor";
case S::invalid_direction: return "invalid_direction";
case S::unresolved: return "unresolved";
case S::no_descent: return "no_descent";
}
return "unknown";
}
inline std::ofstream Open(const std::filesystem::path &path) {
if (std::filesystem::exists(path)) throw std::runtime_error("Refusing to overwrite positivity probe output.");
std::ofstream stream(path);
stream.exceptions(std::ios::badbit | std::ios::failbit);
stream << std::setprecision(17);
return stream;
}
inline void Save(const std::filesystem::path &path,const mfem::Vector &values) {
auto stream = Open(path); stream << values.Size() << '\n';
for (int i = 0; i < values.Size(); ++i) stream << values(i) << '\n';
}
inline double Difference(const mfem::Vector &a,const mfem::Vector &b) {
if (a.Size() != b.Size()) return std::numeric_limits<double>::infinity();
mfem::Vector delta(a); delta -= b; return delta.Norml2();
}
}
template <class State>
void ProbePolynomialEnthalpy(State &s,const mean_field::fem::FEM &f,
const mfem::Vector &normalizedBase,const mfem::Vector &normalizedDirection,
const std::filesystem::path &output) {
using namespace mean_field;
namespace detail = polynomial_probe_detail;
using Schema = utils::domain::CoreEnvelopeVacuumDomainSchema;
using Domain = field::FieldDomainT<field::Enthalpy>;
int ranks = 0;
if (MPI_Comm_size(s.Problem().GetCommunicator(),&ranks) != MPI_SUCCESS || ranks != 1)
throw std::invalid_argument("Frozen polynomial positivity diagnostics require one rank.");
const auto start = std::chrono::steady_clock::now();
const mfem::Vector acceptedPhysical(s.AcceptedPhysicalState()), acceptedNormalized(s.acceptedNormalizedState),
acceptedResidual(s.acceptedNormalizedResidual), savedCorrection(s.normalizedCorrection),
base(normalizedBase), originalDirection(normalizedDirection);
int preparations = 0;
auto restore = [&]() {
s.trialNormalizedState = base;
++preparations;
if (!s.PrepareTrial()) throw std::runtime_error("Frozen positivity base failed production preparation.");
};
auto finish = [&]() {
restore(); s.physicalInverse->Refresh(); s.normalizedCorrection = savedCorrection;
};
try {
restore();
const mfem::Vector baseResidual(s.trialNormalizedResidual);
using Problem = std::remove_cvref_t<decltype(s.Problem())>;
using Form = typename Problem::FormType;
constexpr int hIndex = utils::blocks::type_index_v<utils::blocks::enthalpy::specific::value,typename Form::value_blocks>;
constexpr utils::blocks::value_block<hIndex> block{};
const int offset = s.Problem().GetManifest().layout().offset(block);
const int size = s.Problem().GetManifest().layout().size(block);
std::vector<int> elements;
for (int e = 0; e < f.mesh->GetNE(); ++e)
if (Schema::template attribute_belongs_to<Domain>(f.mesh->GetAttribute(e))) elements.push_back(e);
const auto &surface = s.Problem().GetPressureSurfaceRows().reduced_dofs();
solver::PreparedEnthalpyAdmissibility prepared(*f.enthalpyFes,
field::make_field_dof_map<field::Enthalpy,Schema>(*f.enthalpyFes),elements,
std::span<const int>(surface.GetData(),surface.Size()));
mfem::Vector physicalBase,physicalDirection,h(size),p(size),anchor(size);
s.normalizedOperator->DenormalizeState(base,physicalBase);
s.normalizedOperator->DenormalizeState(originalDirection,physicalDirection);
for (int i = 0; i < size; ++i) {
h(i) = physicalBase(offset+i); p(i) = physicalDirection(offset+i);
anchor(i) = acceptedPhysical(offset+i);
}
auto certificates = detail::Open(output / "polynomial_certificates.csv");
certificates << "state,status,lower_bound,upper_bound,visited_subcells,maximum_depth,witness_element,x,y,z,seconds\n";
auto check = [&](const char *name,const mfem::Vector &values) {
const auto before = std::chrono::steady_clock::now();
const auto report = prepared.Check(values);
certificates << name << ',' << detail::Status(report.status) << ',' << report.lowerBound << ','
<< report.upperBound << ',' << report.visitedSubcells << ',' << report.maximumDepth << ','
<< report.witnessElement << ',' << report.witnessReferencePoint[0] << ','
<< report.witnessReferencePoint[1] << ',' << report.witnessReferencePoint[2] << ','
<< std::chrono::duration<double>(std::chrono::steady_clock::now()-before).count() << '\n';
certificates.flush(); return report;
};
check("frozen_base",h); check("context_seed_anchor",anchor);
mfem::Vector fullCandidate(h); fullCandidate += p;
check("original_full_candidate",fullCandidate);
const auto repair = prepared.MinimumRepairFraction(h,anchor,p);
auto summary = detail::Open(output / "polynomial_repair.csv");
summary << "status,minimum_safe_fraction,base_status,anchor_status,candidate_status\n"
<< detail::RepairStatus(repair.status) << ',' << repair.minimumSafeFraction << ','
<< detail::Status(repair.base.status) << ',' << detail::Status(repair.anchor.status) << ','
<< detail::Status(repair.candidate.status) << '\n';
summary.flush();
auto trials = detail::Open(output / "polynomial_repair_trials.csv");
trials << "fraction,alpha,certificate,prepared,reason,stage,eos_code,residual_norm,linear_model_norm,merit_slope,direction_change\n";
auto evaluate = [&](double fraction,double alpha,const mfem::Vector &direction) {
restore();
mfem::Vector action(s.Problem().EquationSize()); s.normalizedOperator->Mult(direction,action);
const double slope = baseResidual*action;
mfem::Vector model(action); model *= alpha; model += baseResidual;
mfem::Vector candidate(base); candidate.Add(alpha,direction);
mfem::Vector physicalCandidate,reduced(size);
s.normalizedOperator->DenormalizeState(candidate,physicalCandidate);
for (int i = 0; i < size; ++i) reduced(i) = physicalCandidate(offset+i);
const auto certificate = prepared.Check(reduced);
s.trialNormalizedState = candidate; ++preparations;
const auto preparation = s.PrepareTrial();
trials << fraction << ',' << alpha << ',' << detail::Status(certificate.status) << ','
<< static_cast<bool>(preparation) << ',';
if (preparation) trials << "-1,-1,-1," << s.trialNormalizedResidual.Norml2();
else trials << int(preparation.error().reason) << ',' << int(preparation.error().stage) << ','
<< int(preparation.error().thermodynamicErrorCode) << ",nan";
trials << ',' << model.Norml2() << ',' << slope << ','
<< detail::Difference(direction,originalDirection) << '\n'; trials.flush();
};
evaluate(0.0,1.0,originalDirection);
if (repair.status == solver::EnthalpyDirectionRepairStatus::feasible) {
mfem::Vector repairedH;
const std::array fractions{repair.minimumSafeFraction,
0.5*(repair.minimumSafeFraction+1.0),1.0};
for (std::size_t i = 0; i < fractions.size(); ++i) {
const double fraction = fractions[i];
const auto report = prepared.ApplyRepairFraction(h,anchor,p,fraction,repairedH);
if (report.status != solver::PolynomialSignStatus::certified_nonnegative) continue;
mfem::Vector repairedPhysical(physicalDirection),repairedNormalized;
for (int j = 0; j < size; ++j) repairedPhysical(offset+j) = repairedH(j);
s.normalizedOperator->NormalizeState(repairedPhysical,repairedNormalized);
for (int j = 0; j < repairedNormalized.Size(); ++j)
if (j < offset || j >= offset+size) repairedNormalized(j) = originalDirection(j);
detail::Save(output / ("polynomial_repaired_direction_"+std::to_string(i)+".txt"),repairedNormalized);
for (double alpha : {1.0,0.5,0.125}) evaluate(fraction,alpha,repairedNormalized);
}
}
finish();
auto checks = detail::Open(output / "polynomial_restoration.csv");
checks << "metric,value\naccepted_physical_difference," << detail::Difference(acceptedPhysical,s.AcceptedPhysicalState())
<< "\naccepted_normalized_difference," << detail::Difference(acceptedNormalized,s.acceptedNormalizedState)
<< "\naccepted_residual_difference," << detail::Difference(acceptedResidual,s.acceptedNormalizedResidual)
<< "\nrestored_residual_difference," << detail::Difference(baseResidual,s.trialNormalizedResidual)
<< "\nrestored_correction_difference," << detail::Difference(savedCorrection,s.normalizedCorrection)
<< "\npreparations," << preparations << "\nseconds,"
<< std::chrono::duration<double>(std::chrono::steady_clock::now()-start).count() << '\n';
if (detail::Difference(acceptedPhysical,s.AcceptedPhysicalState()) != 0.0 ||
detail::Difference(acceptedNormalized,s.acceptedNormalizedState) != 0.0 ||
detail::Difference(acceptedResidual,s.acceptedNormalizedResidual) != 0.0 ||
detail::Difference(baseResidual,s.trialNormalizedResidual) != 0.0)
throw std::runtime_error("Polynomial positivity diagnostics changed an accepted state or failed restoration.");
} catch (...) {
const auto error = std::current_exception();
finish(); std::rethrow_exception(error);
}
}
}

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@@ -135,6 +135,11 @@ export namespace mean_field::solver {
EnthalpyAdmissibilityOptions options = {}) const {
enthalpy_detail::ValidateOptions(options);
auto coefficients = Transform(nodalValues);
double rootLower = std::numeric_limits<double>::infinity(), rootUpper = -rootLower;
for (const auto &coefficient : coefficients) {
rootLower = std::min(rootLower,coefficient.lo);
rootUpper = std::max(rootUpper,coefficient.hi);
}
struct Cell { std::vector<Interval> coefficients; int depth; std::array<double,3> lo, hi; };
std::vector<Cell> pending;
pending.push_back({std::move(coefficients), 0, {0,0,0}, {1,1,1}});
@@ -164,8 +169,8 @@ export namespace mean_field::solver {
}
if (cell.coefficients[index].hi < 0.0) {
report.status = PolynomialSignStatus::negative;
report.lowerBound = lower;
report.upperBound = upper;
report.lowerBound = rootLower;
report.upperBound = rootUpper;
for (int axis = 0; axis < Dimension; ++axis)
report.witnessReferencePoint[axis] = (corner & (1<<axis)) ? cell.hi[axis] : cell.lo[axis];
return report;
@@ -433,6 +438,14 @@ export namespace mean_field::solver {
if (report.anchor.status != PolynomialSignStatus::certified_nonnegative || !ZeroTrace(anchor)) {
report.status = EnthalpyDirectionRepairStatus::invalid_anchor; return report;
}
bool finiteDirection = true;
for (int i = 0; i < direction.Size(); ++i)
finiteDirection = finiteDirection && std::isfinite(direction(i));
if (enthalpy_detail::CollectiveMaximum(finiteDirection ? 0 : 1,m_space->GetComm())) {
report.status = EnthalpyDirectionRepairStatus::invalid_direction;
report.candidate.status = PolynomialSignStatus::non_finite;
return report;
}
mfem::Vector candidate(base); candidate += direction;
for (int row : m_zeroTrace) candidate(row) = 0.0;
report.candidate = Check(candidate);

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@@ -138,6 +138,7 @@ TEST_CASE("Prepared admissibility preserves shared true DOFs and rejects an inva
const auto base = fixture.Project([](const mfem::Vector &) { return 1.0; });
const auto anchor = fixture.Project([](const mfem::Vector &p) { return 1.0+0.2*p(1); });
const auto direction = fixture.Project([](const mfem::Vector &p) { return -2.0-p(0)+0.5*p(2); });
const mfem::Vector savedBase(base), savedAnchor(anchor), savedDirection(direction);
const auto repair = prepared.MinimumRepairFraction(base,anchor,direction);
REQUIRE(repair.status == EnthalpyDirectionRepairStatus::feasible);
REQUIRE(repair.minimumSafeFraction > 0.0);
@@ -149,6 +150,12 @@ TEST_CASE("Prepared admissibility preserves shared true DOFs and rejects an inva
CHECK(prepared.Check(candidate).status == PolynomialSignStatus::certified_nonnegative);
for (int i = 0; i < repaired.Size(); ++i)
CHECK(repaired(i) == Catch::Approx((1.0-beta)*direction(i)+beta*(anchor(i)-base(i))));
for (int i = 0; i < base.Size(); ++i) {
CHECK(base(i) == savedBase(i)); CHECK(anchor(i) == savedAnchor(i));
CHECK(direction(i) == savedDirection(i));
}
const auto repeated = prepared.MinimumRepairFraction(base,anchor,direction);
CHECK(repeated.minimumSafeFraction == repair.minimumSafeFraction);
mfem::Vector invalid(base); invalid *= -1.0;
CHECK(prepared.MinimumRepairFraction(invalid,anchor,direction).status ==
EnthalpyDirectionRepairStatus::invalid_base);
@@ -181,6 +188,10 @@ TEST_CASE("Feasible direction repair enforces exact homogeneous trace and reject
REQUIRE(prepared.ApplyRepairFraction(base,anchor,direction,1.0,repaired).status ==
PolynomialSignStatus::certified_nonnegative);
for (int row : boundary) CHECK(repaired(row) == 0.0);
auto nonfiniteDirection = direction;
for (int row : boundary) nonfiniteDirection(row) = std::numeric_limits<double>::quiet_NaN();
CHECK(prepared.MinimumRepairFraction(base,anchor,nonfiniteDirection).status ==
EnthalpyDirectionRepairStatus::invalid_direction);
auto invalidTrace = base;
for (int row : boundary) invalidTrace(row) = 1.0e-20;
CHECK(prepared.MinimumRepairFraction(invalidTrace,anchor,direction).status ==