feat(surface): major work on implementing surface constraints in a presciption agnostic manner

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2026-08-30 16:41:14 -04:00
parent 36adfa1174
commit 0a7f18c5c7
95 changed files with 30144 additions and 25766 deletions

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module;
#include <algorithm>
#include <array>
#include <cmath>
#include <cstdint>
#include <iostream>
#include <limits>
#include <string>
#include <utility>
#include <mfem.hpp>
#include <mpi.h>
export module experiment.stellar_null_space;
import mean_field;
import test_helpers;
export namespace experiment::null_space {
using Form = mean_field::utils::blocks::barotropic_equilibrium_form;
using DomainSchema = mean_field::utils::domain::CoreEnvelopeVacuumDomainSchema;
using Model = mean_field::models::StellarModel<mean_field::models::structure::PolytropicStructure>;
constexpr auto densityValue =
mean_field::utils::blocks::get_value_block<Form>(mean_field::utils::blocks::density_field.mass_term);
constexpr auto displacementValue =
mean_field::utils::blocks::get_value_block<Form>(mean_field::utils::blocks::displacement_field.geometry_term);
constexpr auto gravityGradientValue =
mean_field::utils::blocks::get_value_block<Form>(mean_field::utils::blocks::gravity_field.gradient_term);
constexpr auto gravityPotentialValue =
mean_field::utils::blocks::get_value_block<Form>(mean_field::utils::blocks::gravity_field.poisson_term);
constexpr auto enthalpyValue =
mean_field::utils::blocks::get_value_block<Form>(mean_field::utils::blocks::enthalpy_field.specific_term);
constexpr auto bernoulliValue = mean_field::utils::blocks::get_value_block<Form>(
mean_field::utils::blocks::barotropic_constant_field.mass_normalization_term
);
constexpr auto gravityGradientResidual =
mean_field::utils::blocks::get_residual_block<Form>(mean_field::utils::blocks::gravity_field.gradient_term);
constexpr auto gravityPotentialResidual =
mean_field::utils::blocks::get_residual_block<Form>(mean_field::utils::blocks::gravity_field.poisson_term);
constexpr auto densityResidual =
mean_field::utils::blocks::get_residual_block<Form>(mean_field::utils::blocks::density_field.mass_term);
constexpr auto displacementResidual = mean_field::utils::blocks::get_residual_block<Form>(
mean_field::utils::blocks::displacement_field.geometry_term
);
constexpr auto enthalpyResidual =
mean_field::utils::blocks::get_residual_block<Form>(mean_field::utils::blocks::enthalpy_field.specific_term);
constexpr auto massResidual = mean_field::utils::blocks::get_residual_block<Form>(
mean_field::utils::blocks::barotropic_constant_field.mass_normalization_term
);
inline constexpr std::array<const char *, 6> residualBlockNames{"gravity_gradient", "gravity_potential", "closure",
"displacement", "hydrostatic", "mass"};
template <int index>
[[nodiscard]] mfem::Vector value_view(
mfem::Vector &vector,
const mean_field::operators::StellarEquilibriumLayout &layout,
const mean_field::utils::blocks::value_block<index> block
) {
return mfem::Vector(vector.GetData() + layout.offset(block), layout.size(block));
}
template <int index>
[[nodiscard]] mfem::Vector const_value_view(
const mfem::Vector &vector,
const mean_field::operators::StellarEquilibriumLayout &layout,
const mean_field::utils::blocks::value_block<index> block
) {
return mfem::Vector(const_cast<mfem::real_t *>(vector.GetData()) + layout.offset(block), layout.size(block));
}
template <int index>
[[nodiscard]] mfem::Vector residual_view(
mfem::Vector &vector,
const mean_field::operators::StellarEquilibriumLayout &layout,
const mean_field::utils::blocks::residual_block<index> block
) {
return mfem::Vector(vector.GetData() + layout.offset(block), layout.size(block));
}
template <int index>
[[nodiscard]] mfem::Vector const_residual_view(
const mfem::Vector &vector,
const mean_field::operators::StellarEquilibriumLayout &layout,
const mean_field::utils::blocks::residual_block<index> block
) {
return mfem::Vector(const_cast<mfem::real_t *>(vector.GetData()) + layout.offset(block), layout.size(block));
}
template <int index>
void assign_value_block(
mfem::Vector &vector,
const mean_field::operators::StellarEquilibriumLayout &layout,
const mean_field::utils::blocks::value_block<index> block,
const mfem::Vector &source
) {
MFEM_VERIFY(source.Size() == layout.size(block), "Null-space experiment received a block with the wrong size.");
value_view(vector, layout, block) = source;
}
[[nodiscard]] inline double global_norm(
const mfem::Vector &vector,
const MPI_Comm communicator
) {
const double localNormSquared = vector * vector;
double globalNormSquared = 0.0;
MPI_Allreduce(&localNormSquared, &globalNormSquared, 1, MPI_DOUBLE, MPI_SUM, communicator);
return std::sqrt(globalNormSquared);
}
inline void report_progress(
const MPI_Comm communicator,
const std::string &message
) {
int rank = 0;
MPI_Comm_rank(communicator, &rank);
if (rank == 0) {
std::cout << "[null-space experiment] " << message << std::endl;
}
}
[[nodiscard]] inline mean_field::operators::StellarEquilibriumDependencies make_dependencies() {
return {
.discretization = {.identity = 2003, .revision = 1},
.density = {.identity = 2011, .revision = 1},
.displacement = {.identity = 2017, .revision = 1},
.gravityGradient = {.identity = 2027, .revision = 1},
.gravityPotential = {.identity = 2029, .revision = 1},
.enthalpy = {.identity = 2039, .revision = 1},
.bernoulliConstant = {.identity = 2053, .revision = 1},
.rotation = {.identity = 2063, .revision = 1},
.targetMass = {.identity = 2069, .revision = 1}
};
}
inline void increment_state_revisions(mean_field::operators::StellarEquilibriumDependencies &dependencies) {
++dependencies.density.revision;
++dependencies.displacement.revision;
++dependencies.gravityGradient.revision;
++dependencies.gravityPotential.revision;
++dependencies.enthalpy.revision;
++dependencies.bernoulliConstant.revision;
}
[[nodiscard]] inline mfem::Vector pack_gravity_state(
const mfem::Vector &density,
const mfem::Vector &displacement,
const mfem::Vector &gravityGradient,
const mfem::Vector &gravityPotential
) {
const std::array<int, 5> offsets{
0, density.Size(), density.Size() + displacement.Size(),
density.Size() + displacement.Size() + gravityGradient.Size(),
density.Size() + displacement.Size() + gravityGradient.Size() + gravityPotential.Size()
};
mfem::Vector packed(offsets.back());
mfem::Vector(packed.GetData() + offsets[0], density.Size()) = density;
mfem::Vector(packed.GetData() + offsets[1], displacement.Size()) = displacement;
mfem::Vector(packed.GetData() + offsets[2], gravityGradient.Size()) = gravityGradient;
mfem::Vector(packed.GetData() + offsets[3], gravityPotential.Size()) = gravityPotential;
return packed;
}
[[nodiscard]] inline Model make_model() {
const double pi = std::acos(-1.0);
const double targetMass = mean_field::utils::MASS;
constexpr double dimensionlessMass = 2.0182359509662283534;
const double polytropicConstant =
pi * mean_field::utils::G * std::pow(targetMass / (4.0 * pi * dimensionlessMass), 2.0 / 3.0);
return Model{
mean_field::models::structure::PolytropicStructure{
mean_field::eos::Polytrope{3.0, polytropicConstant}, targetMass
},
mean_field::surface::ConstantPressureSurface{mean_field::eos::PressureValue{0.0}}
};
}
class N3Equilibrium final {
public:
explicit N3Equilibrium(mean_field::utils::Args args)
: m_args(std::move(args)),
m_fem(
mean_field::fem::setup_fem(
m_args.mesh_file,
m_args,
0
)
),
m_model(make_model()),
m_operator(
m_fem,
*m_fem.domainMapperStateless,
m_model
),
m_state(m_operator.GetLayout().value_offsets().Last()),
m_dependencies(make_dependencies()) {
MFEM_VERIFY(m_fem.okay(), "The null-space experiment could not construct the finite-element problem.");
m_state = 0.0;
initialize_state();
}
[[nodiscard]] mean_field::fem::FEM &fem() noexcept {
return m_fem;
}
[[nodiscard]] const mean_field::fem::FEM &fem() const noexcept {
return m_fem;
}
[[nodiscard]] mean_field::operators::PreparedStellarEquilibriumOperator &stellar_operator() noexcept {
return m_operator;
}
[[nodiscard]] const mean_field::operators::PreparedStellarEquilibriumOperator &
stellar_operator() const noexcept {
return m_operator;
}
[[nodiscard]] const mfem::Vector &state() const noexcept {
return m_state;
}
[[nodiscard]] mean_field::physics::RigidRotation rotation(const double fractionOfKeplerian) const {
const double radius = mean_field::utils::RADIUS;
const double mass = mean_field::utils::MASS;
const double keplerianSpeed = std::sqrt(mean_field::utils::G * mass / (radius * radius * radius));
mfem::Vector angularVelocity(3);
angularVelocity = 0.0;
angularVelocity(2) = fractionOfKeplerian * keplerianSpeed;
mfem::Vector center(3);
center = 0.0;
return mean_field::physics::RigidRotation(angularVelocity, center);
}
void prepare(
const mfem::Vector &state,
const mean_field::physics::RigidRotation &rotation
) {
m_currentState = state;
increment_state_revisions(m_dependencies);
++m_dependencies.rotation.revision;
m_operator.Prepare(state, m_dependencies, rotation);
}
[[nodiscard]] mfem::Vector unpinned_residual() const {
const auto &layout = m_operator.GetLayout();
const mfem::Vector reducedDensity = const_value_view(m_currentState, layout, densityValue);
const mfem::Vector displacement = const_value_view(m_currentState, layout, displacementValue);
const mfem::Vector gravityGradient = const_value_view(m_currentState, layout, gravityGradientValue);
const mfem::Vector gravityPotential = const_value_view(m_currentState, layout, gravityPotentialValue);
const mfem::Vector gravityState =
pack_gravity_state(reducedDensity, displacement, gravityGradient, gravityPotential);
mfem::Vector gravity;
mfem::Vector closure;
mfem::Vector displacementRows;
mfem::Vector hydrostatic;
mfem::Vector mass;
m_operator.GetGravityOperator().Mult(gravityState, gravity);
m_operator.GetBarotropicClosureOperator().BuildResidual(closure);
m_operator.GetDisplacementOperator().BuildResidual(displacementRows);
m_operator.GetHydrostaticOperator().BuildResidual(hydrostatic);
m_operator.GetSurfaceConstraintOperator().ApplyResidualRows(hydrostatic);
m_operator.GetMassNormalizationOperator().BuildResidual(mass);
return pack_residual(gravity, closure, displacementRows, hydrostatic, mass);
}
[[nodiscard]] mfem::Vector unpinned_jacobian_action(const mfem::Vector &direction) const {
const auto &layout = m_operator.GetLayout();
const mfem::Vector reducedDensityDirection = const_value_view(direction, layout, densityValue);
const mfem::Vector displacementDirection = const_value_view(direction, layout, displacementValue);
const mfem::Vector gravityGradientDirection = const_value_view(direction, layout, gravityGradientValue);
const mfem::Vector gravityPotentialDirection = const_value_view(direction, layout, gravityPotentialValue);
const mfem::Vector reducedEnthalpyDirection = const_value_view(direction, layout, enthalpyValue);
const mfem::Vector bernoulliDirection = const_value_view(direction, layout, bernoulliValue);
const mfem::Vector gravityDirection = pack_gravity_state(
reducedDensityDirection, displacementDirection, gravityGradientDirection, gravityPotentialDirection
);
mfem::Vector gravity;
mfem::Vector closure;
mfem::Vector displacementRows;
mfem::Vector hydrostatic;
mfem::Vector mass;
m_operator.GetGravityJacobianOperator().Mult(gravityDirection, gravity);
m_operator.GetBarotropicClosureOperator().Mult(
reducedDensityDirection, reducedEnthalpyDirection, displacementDirection, closure
);
m_operator.GetDisplacementOperator().ApplyCompleteJacobianAction(
reducedDensityDirection, displacementDirection, gravityGradientDirection, reducedEnthalpyDirection,
displacementRows
);
m_operator.GetHydrostaticOperator().ApplyCompleteJacobianAction(
reducedEnthalpyDirection, gravityPotentialDirection, bernoulliDirection(0), displacementDirection,
hydrostatic
);
m_operator.GetSurfaceConstraintOperator().ApplyJacobianRows(reducedEnthalpyDirection, hydrostatic);
m_operator.GetMassNormalizationOperator().ApplyCompleteJacobianAction(
reducedDensityDirection, displacementDirection, mass
);
return pack_residual(gravity, closure, displacementRows, hydrostatic, mass);
}
private:
void initialize_state() {
report_progress(m_fem.mesh->GetComm(), "constructing the analytic n=3 Lane-Emden state");
constexpr double surfaceCoordinate = 6.8968486193769603755;
constexpr int radialSampleCount = 8192;
const double pi = std::acos(-1.0);
const double radius = mean_field::utils::RADIUS;
const double targetMass = mean_field::utils::MASS;
constexpr double dimensionlessMass = 2.0182359509662283534;
const double polytropicConstant =
pi * mean_field::utils::G * std::pow(targetMass / (4.0 * pi * dimensionlessMass), 2.0 / 3.0);
const double centralDensity =
std::pow(surfaceCoordinate * std::sqrt(polytropicConstant / (pi * mean_field::utils::G)) / radius, 3.0);
const mean_field::models::structure::StructureSeed seed =
m_model.makeInitialSeed({.centralDensity = centralDensity, .radialSampleCount = radialSampleCount});
const auto interpolate = [](const mfem::Vector &radii, const mfem::Vector &values, const double r) {
if (r <= radii(0)) {
return values(0);
}
const int finalIndex = radii.Size() - 1;
if (r >= radii(finalIndex)) {
return values(finalIndex);
}
int lower = 0;
int upper = finalIndex;
while (upper - lower > 1) {
const int middle = lower + (upper - lower) / 2;
if (radii(middle) <= r) {
lower = middle;
} else {
upper = middle;
}
}
const double fraction = (r - radii(lower)) / (radii(upper) - radii(lower));
return (1.0 - fraction) * values(lower) + fraction * values(upper);
};
mfem::FunctionCoefficient densityCoefficient([&seed, &interpolate](const mfem::Vector &position) {
const double r = position.Norml2();
return r >= seed.stellarRadius ? 0.0 : interpolate(seed.radius, seed.density, r);
});
mfem::FunctionCoefficient enthalpyCoefficient([&seed, &interpolate](const mfem::Vector &position) {
const double r = position.Norml2();
return r >= seed.stellarRadius ? 0.0 : interpolate(seed.radius, seed.enthalpy, r);
});
mfem::ParGridFunction densityField(m_fem.densityFes.get());
mfem::ParGridFunction enthalpyField(m_fem.enthalpyFes.get());
mfem::ParGridFunction displacementField(m_fem.displacementFes.get());
densityField = 0.0;
enthalpyField = 0.0;
displacementField = 0.0;
densityField.ProjectCoefficient(densityCoefficient);
enthalpyField.ProjectCoefficient(enthalpyCoefficient);
*m_fem.displacement = displacementField;
report_progress(m_fem.mesh->GetComm(), "solving the gravity field for the seed state");
const mean_field::physics::GravitySolution gravity =
mean_field::physics::solve_gravity_field(m_fem, m_args, densityField, displacementField);
mfem::Vector densityTrue;
mfem::Vector enthalpyTrue;
mfem::Vector displacementTrue;
mfem::Vector gravityGradientTrue;
mfem::Vector gravityPotentialTrue;
densityField.GetTrueDofs(densityTrue);
enthalpyField.GetTrueDofs(enthalpyTrue);
displacementField.GetTrueDofs(displacementTrue);
gravity.gradPhi.GetTrueDofs(gravityGradientTrue);
gravity.phi.GetTrueDofs(gravityPotentialTrue);
const auto &layout = m_operator.GetLayout();
const mean_field::field::FieldDofMap densityMap =
mean_field::field::make_field_dof_map<mean_field::field::Density, DomainSchema>(*m_fem.densityFes);
const mean_field::field::FieldDofMap enthalpyMap =
mean_field::field::make_field_dof_map<mean_field::field::Enthalpy, DomainSchema>(*m_fem.enthalpyFes);
assign_value_block(m_state, layout, densityValue, densityMap.gather(densityTrue));
assign_value_block(m_state, layout, displacementValue, displacementTrue);
assign_value_block(m_state, layout, gravityGradientValue, gravityGradientTrue);
assign_value_block(m_state, layout, gravityPotentialValue, gravityPotentialTrue);
assign_value_block(m_state, layout, enthalpyValue, enthalpyMap.gather(enthalpyTrue));
value_view(m_state, layout, bernoulliValue)(0) = -mean_field::utils::G * targetMass / radius;
m_currentState = m_state;
prepare(m_state, rotation(0.0));
report_progress(m_fem.mesh->GetComm(), "analytic state is prepared");
}
[[nodiscard]] mfem::Vector pack_residual(
const mfem::Vector &gravity,
const mfem::Vector &closure,
const mfem::Vector &displacementRows,
const mfem::Vector &hydrostatic,
const mfem::Vector &mass
) const {
const auto &layout = m_operator.GetLayout();
mfem::Vector result(layout.residual_offsets().Last());
result = 0.0;
const mfem::Vector gravityGradient(gravity.GetData(), layout.size(gravityGradientResidual));
const mfem::Vector gravityPotential(
gravity.GetData() + layout.size(gravityGradientResidual), layout.size(gravityPotentialResidual)
);
residual_view(result, layout, gravityGradientResidual) = gravityGradient;
residual_view(result, layout, gravityPotentialResidual) = gravityPotential;
residual_view(result, layout, densityResidual) = closure;
residual_view(result, layout, displacementResidual) = displacementRows;
residual_view(result, layout, enthalpyResidual) = hydrostatic;
residual_view(result, layout, massResidual) = mass;
return result;
}
mean_field::utils::Args m_args;
mean_field::fem::FEM m_fem;
Model m_model;
mean_field::operators::PreparedStellarEquilibriumOperator m_operator;
mfem::Vector m_state;
mfem::Vector m_currentState;
mean_field::operators::StellarEquilibriumDependencies m_dependencies;
};
enum class RigidModeKind : std::uint8_t { translation, rotation };
struct RigidMode final {
std::string name;
RigidModeKind kind;
int axis;
mfem::Vector direction;
};
[[nodiscard]] inline std::array<
RigidMode,
6>
make_rigid_modes(const N3Equilibrium &fixture) {
const auto &fem = fixture.fem();
const auto &layout = fixture.stellar_operator().GetLayout();
std::array<RigidMode, 6> modes;
for (int axis = 0; axis < 3; ++axis) {
mfem::ParGridFunction translation(fem.displacementFes.get());
mfem::Vector translationValue(3);
translationValue = 0.0;
translationValue(axis) = 1.0;
mfem::VectorConstantCoefficient coefficient(translationValue);
translation.ProjectCoefficient(coefficient);
mfem::Vector translationTrue;
translation.GetTrueDofs(translationTrue);
mfem::Vector direction(layout.value_offsets().Last());
direction = 0.0;
assign_value_block(direction, layout, displacementValue, translationTrue);
modes[axis] = RigidMode{
.name = std::string("translation_") + static_cast<char>('x' + axis),
.kind = RigidModeKind::translation,
.axis = axis,
.direction = std::move(direction)
};
}
for (int axis = 0; axis < 3; ++axis) {
mfem::ParGridFunction rotation(fem.displacementFes.get());
mfem::VectorFunctionCoefficient coefficient(3, [axis](const mfem::Vector &position, mfem::Vector &value) {
value.SetSize(3);
value = 0.0;
const int first = (axis + 1) % 3;
const int second = (axis + 2) % 3;
value(first) = -position(second);
value(second) = position(first);
});
rotation.ProjectCoefficient(coefficient);
mfem::Vector rotationTrue;
rotation.GetTrueDofs(rotationTrue);
mfem::Vector direction(layout.value_offsets().Last());
direction = 0.0;
assign_value_block(direction, layout, displacementValue, rotationTrue);
modes[3 + axis] = RigidMode{
.name = std::string("rotation_") + static_cast<char>('x' + axis),
.kind = RigidModeKind::rotation,
.axis = axis,
.direction = std::move(direction)
};
}
return modes;
}
[[nodiscard]] inline std::array<
double,
6>
residual_block_norms(
const mfem::Vector &action,
const mean_field::operators::StellarEquilibriumLayout &layout,
const MPI_Comm communicator
) {
return {
global_norm(const_residual_view(action, layout, gravityGradientResidual), communicator),
global_norm(const_residual_view(action, layout, gravityPotentialResidual), communicator),
global_norm(const_residual_view(action, layout, densityResidual), communicator),
global_norm(const_residual_view(action, layout, displacementResidual), communicator),
global_norm(const_residual_view(action, layout, enthalpyResidual), communicator),
global_norm(const_residual_view(action, layout, massResidual), communicator)
};
}
} // namespace experiment::null_space