feat: integrate checked thermal shell operators

This commit is contained in:
KOKO\Mimi
2026-09-29 19:43:56 +09:00
11 changed files with 2009 additions and 0 deletions
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#ifndef FESA_ANALYSIS_THERMAL_TIME_GRID_H_
#define FESA_ANALYSIS_THERMAL_TIME_GRID_H_
#include <cstdint>
#include "fesa/core/status.h"
namespace fesa {
/// @brief Carries one stored time and its actual integration coefficient.
struct ThermalTimeFrame {
double time;
double delta;
};
/// @brief Stores an O(1) fixed-increment grid with exact input-cell endpoint
/// tests.
class ThermalTimeGrid final {
public:
/// @brief Checks finite positive controls and the uint32 INC bound before
/// use.
static Result<ThermalTimeGrid> Create(double period, double increment,
std::uint32_t maximum = 100U);
/// @brief Returns the number of completed increments, excluding initial time.
std::uint32_t Count() const noexcept;
/// @brief Returns fl(index * nominal increment), or the exact final input
/// time.
/// @pre index is in [0, Count()].
double Time(std::uint32_t index) const noexcept;
/// @brief Returns the actual coefficient, never a difference of stored times.
/// @pre index is in [1, Count()].
double Delta(std::uint32_t index) const noexcept;
/// @brief Checks index, finite values and strict increase for one frame in
/// O(1).
Result<ThermalTimeFrame> Frame(std::uint32_t index) const;
private:
/// @brief Stores controls only after count and terminal interval validation.
ThermalTimeGrid(double period, double increment, std::uint32_t count,
double final_delta);
double period_;
double increment_;
std::uint32_t count_;
double final_delta_;
};
} // namespace fesa
#endif // FESA_ANALYSIS_THERMAL_TIME_GRID_H_
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#ifndef FESA_ELEMENTS_THERMAL_SHELL_H_
#define FESA_ELEMENTS_THERMAL_SHELL_H_
#include <array>
#include "fesa/core/source_identity.h"
#include "fesa/core/status.h"
#include "fesa/math/matrix.h"
#include "fesa/math/vector3.h"
namespace fesa {
/// @brief Holds global heat flux at four CCW surface points times six traces.
/// @note Trace order is -1+, -.5, 0-, 0+, .5, 1-. Frame columns are e1,e2,n.
struct ThermalShellRecovery {
std::array<Vector3, 24> global_flux;
std::array<std::array<Vector3, 3>, 4> frames;
};
/// @brief Owns checked local Q4 times two-segment P2 transient-heat operators.
/// @note Twenty DOFs are node-major, five stations bottom to top per node.
class ThermalShell final {
public:
/// @brief Builds finite consistent capacity/conduction and flux operators.
/// @param coordinates Original midsurface Cartesian coordinates, without
/// projection.
/// @return A complete kernel or a source-identified geometry/material
/// failure.
static Result<ThermalShell> Create(SourceEntityId source,
std::array<EntityIndex, 4> node_indices,
const std::array<Vector3, 4>& coordinates,
double conductivity, double density,
double specific_heat, double thickness,
SourceLocation location = {});
/// @brief Returns the original element identity.
const SourceEntityId& SourceId() const noexcept;
/// @brief Returns Domain node indices, not equation numbers.
const std::array<EntityIndex, 4>& NodeIndices() const noexcept;
/// @brief Returns the node-major conductivity matrix [power/temperature].
const Matrix& Conductivity() const noexcept;
/// @brief Returns the consistent capacity matrix [energy/temperature].
const Matrix& Capacity() const noexcept;
/// @brief Returns componentwise outward roundoff bounds, excluding quadrature
/// error.
const Matrix& ConductivityError() const noexcept;
/// @brief Returns componentwise outward roundoff bounds, excluding quadrature
/// error.
const Matrix& CapacityError() const noexcept;
/// @brief Evaluates q=-k*grad(T) without averaging the two midsurface traces.
/// @return Finite global fluxes and right-handed frames or source-identified
/// failure.
Result<ThermalShellRecovery> Recover(
const std::array<double, 20>& temperature) const;
private:
/// @brief Initializes an unpublished candidate whose operators are filled by
/// Create.
ThermalShell(SourceEntityId source, std::array<EntityIndex, 4> node_indices,
SourceLocation location, double conductivity);
SourceEntityId source_;
std::array<EntityIndex, 4> node_indices_;
SourceLocation location_;
double conductivity_value_;
Matrix conductivity_{20U, 20U};
Matrix capacity_{20U, 20U};
Matrix conductivity_error_{20U, 20U};
Matrix capacity_error_{20U, 20U};
std::array<std::array<Vector3, 20>, 24> gradients_{};
std::array<std::array<Vector3, 3>, 4> frames_{};
};
} // namespace fesa
#endif // FESA_ELEMENTS_THERMAL_SHELL_H_
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#include "fesa/analysis/thermal_time_grid.h"
#include <array>
#include <cmath>
#include <cstdint>
#include <cstring>
#include <limits>
namespace fesa {
namespace {
// Fixed four base-2^32 digits. Contract bounds all exact values to 122 bits.
struct UInt128 {
std::array<std::uint32_t, 4> digit{};
};
/// @brief Orders unsigned integers from their most significant digit.
int Compare(const UInt128& a, const UInt128& b) {
for (int i = 3; i >= 0; --i) {
if (a.digit[i] != b.digit[i]) return a.digit[i] < b.digit[i] ? -1 : 1;
}
return 0;
}
/// @brief Adds with explicit carry; false means the fixed storage overflowed.
bool Add(const UInt128& a, const UInt128& b, UInt128& result) {
std::uint64_t carry = 0;
for (std::size_t i = 0; i < 4; ++i) {
const std::uint64_t sum = std::uint64_t{a.digit[i]} + b.digit[i] + carry;
result.digit[i] = static_cast<std::uint32_t>(sum);
carry = sum >> 32;
}
return carry == 0;
}
/// @brief Subtracts nonnegative magnitudes with explicit borrow.
bool Subtract(const UInt128& a, const UInt128& b, UInt128& result) {
std::uint64_t borrow = 0;
for (std::size_t i = 0; i < 4; ++i) {
const std::uint64_t sub = std::uint64_t{b.digit[i]} + borrow;
result.digit[i] =
static_cast<std::uint32_t>(std::uint64_t{a.digit[i]} - sub);
borrow = std::uint64_t{a.digit[i]} < sub ? 1U : 0U;
}
return borrow == 0;
}
/// @brief Places a significand on the exact 2^-88 scaled lattice.
bool Shift(std::uint64_t value, int shift, UInt128& result) {
result = {};
if (shift < 0) return false;
for (int bit = 0; bit < 64; ++bit) {
if ((value & (std::uint64_t{1} << bit)) == 0) continue;
const int target = bit + shift;
if (target >= 128) return false;
result.digit[target / 32] |= std::uint32_t{1} << (target % 32);
}
return true;
}
/// @brief Multiplies by at most 2^32+1 using bounded schoolbook products.
bool Multiply(const UInt128& a, std::uint64_t multiplier, UInt128& result) {
result = {};
for (std::size_t j = 0; j < 2; ++j) {
const auto factor = static_cast<std::uint32_t>(multiplier >> (32 * j));
std::uint64_t carry = 0;
for (std::size_t i = 0; i < 4; ++i) {
if (i + j >= 4) {
if (a.digit[i] != 0 && factor != 0) return false;
continue;
}
const std::uint64_t product =
std::uint64_t{a.digit[i]} * factor + result.digit[i + j] + carry;
result.digit[i + j] = static_cast<std::uint32_t>(product);
carry = product >> 32;
}
if (carry != 0) return false;
}
return true;
}
struct Cell {
UInt128 center;
UInt128 lower;
UInt128 upper;
bool closed;
};
/// @brief Constructs ORIGINAL binary64 cells, including subnormal/maxfinite
/// gaps.
bool MakeCell(double value, int period_exponent, Cell& cell) {
std::uint64_t bits = 0;
std::memcpy(&bits, &value, sizeof(bits));
const int exponent_bits = static_cast<int>((bits >> 52) & 0x7ffU);
const std::uint64_t fraction = bits & ((std::uint64_t{1} << 52) - 1);
const std::uint64_t significand =
exponent_bits == 0 ? fraction : fraction + (std::uint64_t{1} << 52);
const int exponent = exponent_bits == 0 ? -1074 : exponent_bits - 1075;
const int lattice_shift = exponent - period_exponent + 88;
UInt128 lower_gap;
UInt128 upper_gap;
// At a normal binade boundary only the predecessor gap is halved. The
// smallest normal has subnormal neighbors with the same original spacing.
const int boundary = fraction == 0 && exponent_bits > 1 ? 1 : 0;
cell.closed = (bits & 1) == 0;
return Shift(significand, lattice_shift, cell.center) &&
Shift(1, lattice_shift - 1 - boundary, lower_gap) &&
Shift(1, lattice_shift - 1, upper_gap) &&
Subtract(cell.center, lower_gap, cell.lower) &&
Add(cell.center, upper_gap, cell.upper);
}
/// @brief Returns source-neutral utility failure for parser/procedure
/// decoration.
Status GridFailure(const char* code, const char* message) {
return Status::Failure(
FailureCategory::kModel,
{{Severity::kError, code, {}, "HEAT TRANSFER", "", message}});
}
} // namespace
Result<ThermalTimeGrid> ThermalTimeGrid::Create(double period, double increment,
std::uint32_t maximum) {
if (!std::isfinite(period) || !std::isfinite(increment) || period <= 0 ||
increment <= 0 || maximum == 0) {
return Result<ThermalTimeGrid>::Failure(
GridFailure("invalid-thermal-time-grid",
"Time controls must be finite and positive."));
}
if (increment >= period) {
return Result<ThermalTimeGrid>::Success(
ThermalTimeGrid{period, increment, 1U, period});
}
const double quotient = period / increment;
const std::uint64_t limit = std::uint64_t{maximum} + 1U;
if (!std::isfinite(quotient) || quotient > static_cast<double>(limit)) {
return Result<ThermalTimeGrid>::Failure(GridFailure(
"thermal-increment-limit", "Thermal increment count exceeds INC."));
}
// No floating-to-integer cast precedes the finite, positive count bound.
std::uint64_t floor = static_cast<std::uint64_t>(std::floor(quotient));
const double fraction = quotient - static_cast<double>(floor);
const std::uint64_t nearest =
floor + ((fraction > .5 || (fraction == .5 && (floor & 1) != 0)) ? 1 : 0);
int exponent = 0;
std::frexp(period, &exponent);
Cell period_cell{};
Cell increment_cell{};
UInt128 lower;
UInt128 upper;
bool exact_ok = MakeCell(period, exponent, period_cell) &&
MakeCell(increment, exponent, increment_cell) &&
Multiply(increment_cell.lower, nearest, lower) &&
Multiply(increment_cell.upper, nearest, upper);
const int first = Compare(period_cell.upper, lower);
const int second = Compare(upper, period_cell.lower);
const bool closed = period_cell.closed && increment_cell.closed;
const bool close = nearest != 0 && (first > 0 || (first == 0 && closed)) &&
(second > 0 || (second == 0 && closed));
std::uint64_t count = nearest;
if (!close && exact_ok) {
UInt128 product;
UInt128 next;
exact_ok = Multiply(increment_cell.center, floor, product) &&
Multiply(increment_cell.center, floor + 1, next);
if (Compare(product, period_cell.center) > 0) {
--floor;
} else if (Compare(next, period_cell.center) <= 0) {
++floor;
}
exact_ok = exact_ok && Multiply(increment_cell.center, floor, product) &&
Multiply(increment_cell.center, floor + 1, next) &&
Compare(product, period_cell.center) <= 0 &&
Compare(next, period_cell.center) > 0;
count = floor + (Compare(product, period_cell.center) == 0 ? 0U : 1U);
}
if (!exact_ok) {
return Result<ThermalTimeGrid>::Failure(GridFailure(
"invalid-thermal-time-grid", "Exact time lattice bounds failed."));
}
if (count == 0 || count > maximum) {
return Result<ThermalTimeGrid>::Failure(GridFailure(
"thermal-increment-limit", "Thermal increment count exceeds INC."));
}
const double last =
close ? increment
: std::fma(-static_cast<double>(count - 1), increment, period);
ThermalTimeGrid grid{period, increment, static_cast<std::uint32_t>(count),
last};
const auto frame = grid.Frame(grid.Count());
if (!frame.HasValue())
return Result<ThermalTimeGrid>::Failure(frame.GetStatus());
// For j <= 2^32, adjacent exact j*d are separated by more than 2^19 ULPs
// (subnormal products are exact). Thus the terminal check also suffices for
// O(1) preflight; every requested frame still checks its own stored interval.
return Result<ThermalTimeGrid>::Success(grid);
}
ThermalTimeGrid::ThermalTimeGrid(double period, double increment,
std::uint32_t count, double final_delta)
: period_{period},
increment_{increment},
count_{count},
final_delta_{final_delta} {}
std::uint32_t ThermalTimeGrid::Count() const noexcept { return count_; }
double ThermalTimeGrid::Time(std::uint32_t index) const noexcept {
return index == count_ ? period_ : static_cast<double>(index) * increment_;
}
double ThermalTimeGrid::Delta(std::uint32_t index) const noexcept {
return index == count_ ? final_delta_ : increment_;
}
Result<ThermalTimeFrame> ThermalTimeGrid::Frame(std::uint32_t index) const {
if (index == 0 || index > count_) {
return Result<ThermalTimeFrame>::Failure(
GridFailure("invalid-thermal-time-frame",
"Completed frame index is outside the grid."));
}
const double time = Time(index);
const double delta = Delta(index);
const double previous = Time(index - 1);
if (!std::isfinite(time) || !std::isfinite(previous) ||
!std::isfinite(delta) || !(time > previous) || !(delta > 0)) {
return Result<ThermalTimeFrame>::Failure(
GridFailure("invalid-thermal-time-frame",
"Stored times must be finite and strictly increasing."));
}
return Result<ThermalTimeFrame>::Success({time, delta});
}
} // namespace fesa
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#ifndef FESA_ELEMENTS_THERMAL_INTERVAL_H_
#define FESA_ELEMENTS_THERMAL_INTERVAL_H_
#include <algorithm>
#include <array>
#include <cmath>
#include <limits>
namespace fesa::thermal_internal {
/// @brief Encloses binary64 operations with one outward nextafter per endpoint.
struct Interval {
double lower = 0;
double upper = 0;
Interval() = default;
explicit Interval(double value) : lower{value}, upper{value} {}
Interval(double low, double high) : lower{low}, upper{high} {}
bool IsFinite() const {
return std::isfinite(lower) && std::isfinite(upper) && lower <= upper;
}
bool ContainsZero() const { return lower <= 0 && upper >= 0; }
};
/// @brief Rounds an operation endpoint toward negative infinity.
inline double Down(double value) {
return std::nextafter(value, -std::numeric_limits<double>::infinity());
}
/// @brief Rounds an operation endpoint toward positive infinity.
inline double Up(double value) {
return std::nextafter(value, std::numeric_limits<double>::infinity());
}
inline Interval operator+(Interval a, Interval b) {
return {Down(a.lower + b.lower), Up(a.upper + b.upper)};
}
inline Interval operator-(Interval a, Interval b) {
return {Down(a.lower - b.upper), Up(a.upper - b.lower)};
}
inline Interval operator*(Interval a, Interval b) {
const std::array<double, 4> products{{a.lower * b.lower, a.lower * b.upper,
a.upper * b.lower, a.upper * b.upper}};
return {Down(*std::min_element(products.begin(), products.end())),
Up(*std::max_element(products.begin(), products.end()))};
}
inline Interval operator/(Interval a, Interval b) {
if (b.ContainsZero())
return {-std::numeric_limits<double>::infinity(),
std::numeric_limits<double>::infinity()};
const std::array<double, 4> quotients{{a.lower / b.lower, a.lower / b.upper,
a.upper / b.lower, a.upper / b.upper}};
return {Down(*std::min_element(quotients.begin(), quotients.end())),
Up(*std::max_element(quotients.begin(), quotients.end()))};
}
/// @brief Encloses the square without introducing negative cancellation bounds.
inline Interval Square(Interval value) {
const double a = value.lower * value.lower;
const double b = value.upper * value.upper;
return {value.ContainsZero() ? 0 : Down(std::min(a, b)), Up(std::max(a, b))};
}
/// @brief Encloses a real square root; negative upper endpoints remain invalid.
inline Interval Sqrt(Interval value) {
return {value.lower <= 0 ? 0 : Down(std::sqrt(value.lower)),
Up(std::sqrt(value.upper))};
}
/// @brief Scales exactly by powers of two, enclosing subnormal loss if present.
inline Interval Scale(Interval value, int exponent) {
const double low = std::ldexp(value.lower, exponent);
const double high = std::ldexp(value.upper, exponent);
const bool low_exact =
std::isfinite(low) && std::ldexp(low, -exponent) == value.lower;
const bool high_exact =
std::isfinite(high) && std::ldexp(high, -exponent) == value.upper;
return {low_exact ? low : Down(low), high_exact ? high : Up(high)};
}
using IntervalVector = std::array<Interval, 3>;
/// @brief Performs componentwise vector addition in fixed Cartesian order.
inline IntervalVector operator+(const IntervalVector& a,
const IntervalVector& b) {
return {{a[0] + b[0], a[1] + b[1], a[2] + b[2]}};
}
/// @brief Performs componentwise vector subtraction in fixed Cartesian order.
inline IntervalVector operator-(const IntervalVector& a,
const IntervalVector& b) {
return {{a[0] - b[0], a[1] - b[1], a[2] - b[2]}};
}
/// @brief Scales a vector by an interval scalar.
inline IntervalVector operator*(Interval s, const IntervalVector& a) {
return {{s * a[0], s * a[1], s * a[2]}};
}
/// @brief Accumulates a three-component inner product in fixed order.
inline Interval Dot(const IntervalVector& a, const IntervalVector& b) {
return (a[0] * b[0] + a[1] * b[1]) + a[2] * b[2];
}
/// @brief Encloses a right-handed Cartesian cross product.
inline IntervalVector Cross(const IntervalVector& a, const IntervalVector& b) {
return {{a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2],
a[0] * b[1] - a[1] * b[0]}};
}
/// @brief Encloses a squared norm as a sum of nonnegative squares.
inline Interval NormSquared(const IntervalVector& a) {
return (Square(a[0]) + Square(a[1])) + Square(a[2]);
}
/// @brief Checks all Cartesian components for finite ordered endpoints.
inline bool IsFinite(const IntervalVector& a) {
return a[0].IsFinite() && a[1].IsFinite() && a[2].IsFinite();
}
} // namespace fesa::thermal_internal
#endif // FESA_ELEMENTS_THERMAL_INTERVAL_H_
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#include "fesa/elements/thermal_shell.h"
#include <algorithm>
#include <array>
#include <cmath>
#include <utility>
#include "thermal_shell_geometry.h"
namespace fesa {
namespace {
using thermal_internal::Interval;
/// @brief Measures the full endpoint deviation from a computed coefficient.
double ErrorBound(Interval interval, double value) {
return thermal_internal::Up(std::max(std::abs(interval.lower - value),
std::abs(interval.upper - value)));
}
} // namespace
ThermalShell::ThermalShell(SourceEntityId source,
std::array<EntityIndex, 4> node_indices,
SourceLocation location, double conductivity)
: source_{std::move(source)},
node_indices_{node_indices},
location_{std::move(location)},
conductivity_value_{conductivity} {}
Result<ThermalShell> ThermalShell::Create(
SourceEntityId source, std::array<EntityIndex, 4> node_indices,
const std::array<Vector3, 4>& coordinates, double conductivity,
double density, double specific_heat, double thickness,
SourceLocation location) {
using namespace thermal_internal;
for (const double property :
{conductivity, density, specific_heat, thickness}) {
if (!(property > 0) || !std::isfinite(property)) {
return Result<ThermalShell>::Failure(
GeometryFailure(source, location, "invalid-thermal-shell-material",
"Thermal properties must be finite and positive."));
}
}
auto sorted = node_indices;
std::sort(sorted.begin(), sorted.end());
if (std::adjacent_find(sorted.begin(), sorted.end()) != sorted.end()) {
return Result<ThermalShell>::Failure(
GeometryFailure(source, location, "invalid-thermal-shell-geometry",
"Patch contains repeated source nodes."));
}
const auto geometry = BuildGeometry(coordinates, source, location);
if (!geometry.HasValue())
return Result<ThermalShell>::Failure(geometry.GetStatus());
ThermalShell kernel{source, node_indices, location, conductivity};
Matrix mass{4, 4};
Matrix surface{4, 4};
std::array<std::array<Interval, 4>, 4> mass_interval{};
std::array<std::array<Interval, 4>, 4> surface_interval{};
const double gauss = std::sqrt(3. / 5.);
const Interval gauss_interval = Sqrt(Interval{3} / Interval{5});
const std::array<double, 3> points{{-gauss, 0., gauss}};
const std::array<Interval, 3> point_intervals{
{Interval{0} - gauss_interval, Interval{0}, gauss_interval}};
const std::array<double, 3> weights{{5. / 9., 8. / 9., 5. / 9.}};
const std::array<Interval, 3> weight_intervals{{Interval{5} / Interval{9},
Interval{8} / Interval{9},
Interval{5} / Interval{9}}};
for (std::size_t x = 0; x < 3; ++x) {
for (std::size_t y = 0; y < 3; ++y) {
const auto result = EvaluateSurface(geometry.Value(), points[x],
points[y], point_intervals[x],
point_intervals[y], source, location);
if (!result.HasValue())
return Result<ThermalShell>::Failure(result.GetStatus());
const auto& point = result.Value();
const double weight = weights[x] * weights[y] * point.jacobian;
const Interval weight_interval =
weight_intervals[x] * weight_intervals[y] * point.jacobian_interval;
for (std::size_t i = 0; i < 4; ++i) {
for (std::size_t j = 0; j < 4; ++j) {
mass(i, j) += point.shape[i] * point.shape[j] * weight;
surface(i, j) += point.gradient[i].Dot(point.gradient[j]) * weight;
mass_interval[i][j] = mass_interval[i][j] +
point.shape_interval[i] *
point.shape_interval[j] * weight_interval;
surface_interval[i][j] =
surface_interval[i][j] +
Dot(point.gradient_interval[i], point.gradient_interval[j]) *
weight_interval;
}
}
}
}
Matrix z0{5, 5};
Matrix z1{5, 5};
std::array<std::array<Interval, 5>, 5> z0_interval{};
std::array<std::array<Interval, 5>, 5> z1_interval{};
constexpr double kZ0[3][3] = {{4, 2, -1}, {2, 16, 2}, {-1, 2, 4}};
constexpr double kZ1[3][3] = {{7, -8, 1}, {-8, 16, -8}, {1, -8, 7}};
for (const std::size_t first : {0U, 2U}) {
for (std::size_t a = 0; a < 3; ++a) {
for (std::size_t b = 0; b < 3; ++b) {
z0(first + a, first + b) += kZ0[a][b] / 30.;
z1(first + a, first + b) += kZ1[a][b] / 3.;
z0_interval[first + a][first + b] = z0_interval[first + a][first + b] +
Interval{kZ0[a][b]} / Interval{30};
z1_interval[first + a][first + b] = z1_interval[first + a][first + b] +
Interval{kZ1[a][b]} / Interval{3};
}
}
}
for (std::size_t i = 0; i < 4; ++i) {
for (std::size_t j = 0; j < 4; ++j) {
for (std::size_t a = 0; a < 5; ++a) {
for (std::size_t b = 0; b < 5; ++b) {
const std::size_t p = 5 * i + a;
const std::size_t q = 5 * j + b;
kernel.capacity_(p, q) =
density * specific_heat * (thickness / 2) * mass(i, j) * z0(a, b);
kernel.conductivity_(p, q) =
conductivity * ((thickness / 2) * surface(i, j) * z0(a, b) +
(2 / thickness) * mass(i, j) * z1(a, b));
const Interval capacity = Interval{density} *
Interval{specific_heat} *
(Interval{thickness} / Interval{2}) *
mass_interval[i][j] * z0_interval[a][b];
const Interval conduction =
Interval{conductivity} *
((Interval{thickness} / Interval{2}) * surface_interval[i][j] *
z0_interval[a][b] +
(Interval{2} / Interval{thickness}) * mass_interval[i][j] *
z1_interval[a][b]);
kernel.capacity_error_(p, q) =
ErrorBound(capacity, kernel.capacity_(p, q));
kernel.conductivity_error_(p, q) =
ErrorBound(conduction, kernel.conductivity_(p, q));
if (!capacity.IsFinite() || !conduction.IsFinite() ||
!std::isfinite(kernel.capacity_(p, q)) ||
!std::isfinite(kernel.conductivity_(p, q)) ||
!std::isfinite(kernel.capacity_error_(p, q)) ||
!std::isfinite(kernel.conductivity_error_(p, q)) ||
(p == q && (!(kernel.capacity_(p, q) > 0) ||
!(kernel.conductivity_(p, q) > 0)))) {
return Result<ThermalShell>::Failure(GeometryFailure(
source, location, "nonfinite-thermal-shell-operator",
"Local matrix/enclosure is not finite or a diagonal lost "
"positivity."));
}
}
}
}
}
const double recovery = 1 / std::sqrt(3.);
const Interval recovery_interval = Interval{1} / Sqrt(Interval{3});
constexpr std::array<double, 4> kXi{{-1, 1, 1, -1}};
constexpr std::array<double, 4> kEta{{-1, -1, 1, 1}};
constexpr std::array<double, 6> kLocal{{-1, 0, 1, -1, 0, 1}};
for (std::size_t ip = 0; ip < 4; ++ip) {
const auto result = EvaluateSurface(
geometry.Value(), kXi[ip] * recovery, kEta[ip] * recovery,
Interval{kXi[ip]} * recovery_interval,
Interval{kEta[ip]} * recovery_interval, source, location);
if (!result.HasValue())
return Result<ThermalShell>::Failure(result.GetStatus());
const auto& point = result.Value();
kernel.frames_[ip] = point.axes;
for (std::size_t trace = 0; trace < 6; ++trace) {
const double s = kLocal[trace];
const std::array<double, 3> shape{
{.5 * s * (s - 1), 1 - s * s, .5 * s * (s + 1)}};
const std::array<double, 3> derivative{{2 * s - 1, -4 * s, 2 * s + 1}};
const std::size_t first = trace < 3 ? 0 : 2;
for (std::size_t i = 0; i < 4; ++i) {
for (std::size_t a = 0; a < 3; ++a) {
const Vector3 gradient =
shape[a] * point.gradient[i] +
(point.shape[i] * (2 / thickness) * derivative[a]) *
point.axes[2];
if (!gradient.IsFinite()) {
return Result<ThermalShell>::Failure(GeometryFailure(
source, location, "nonfinite-thermal-shell-recovery",
"Flux gradient is not finite."));
}
kernel.gradients_[6 * ip + trace][5 * i + first + a] = gradient;
}
}
}
}
return Result<ThermalShell>::Success(std::move(kernel));
}
const SourceEntityId& ThermalShell::SourceId() const noexcept {
return source_;
}
const std::array<EntityIndex, 4>& ThermalShell::NodeIndices() const noexcept {
return node_indices_;
}
const Matrix& ThermalShell::Conductivity() const noexcept {
return conductivity_;
}
const Matrix& ThermalShell::Capacity() const noexcept { return capacity_; }
const Matrix& ThermalShell::ConductivityError() const noexcept {
return conductivity_error_;
}
const Matrix& ThermalShell::CapacityError() const noexcept {
return capacity_error_;
}
Result<ThermalShellRecovery> ThermalShell::Recover(
const std::array<double, 20>& temperature) const {
for (const double value : temperature) {
if (!std::isfinite(value)) {
return Result<ThermalShellRecovery>::Failure(
thermal_internal::GeometryFailure(
source_, location_, "nonfinite-thermal-shell-temperature",
"Recovery temperature is not finite."));
}
}
ThermalShellRecovery recovery{};
recovery.frames = frames_;
for (std::size_t row = 0; row < 24; ++row) {
Vector3 gradient;
for (std::size_t p = 0; p < 20; ++p)
gradient = gradient + temperature[p] * gradients_[row][p];
recovery.global_flux[row] = -conductivity_value_ * gradient;
if (!recovery.global_flux[row].IsFinite()) {
return Result<ThermalShellRecovery>::Failure(
thermal_internal::GeometryFailure(
source_, location_, "nonfinite-thermal-shell-flux",
"Recovered heat flux is not finite."));
}
}
return Result<ThermalShellRecovery>::Success(recovery);
}
} // namespace fesa
@@ -0,0 +1,431 @@
#include "thermal_shell_geometry.h"
#include <algorithm>
#include <array>
#include <cmath>
#include <cstdint>
#include <limits>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <vector>
#include "fesa/model/model_types.h"
namespace fesa {
namespace thermal_internal {
namespace {
/// @brief Represents an exact input vector by three singleton intervals.
IntervalVector Singleton(const Vector3& point) {
return {{Interval{point.X()}, Interval{point.Y()}, Interval{point.Z()}}};
}
/// @brief Checks a candidate direction against the ORIGINAL interval geometry.
bool Certify(const Geometry& geometry, Vector3 direction, double& lower) {
const double magnitude = direction.Norm();
if (!(magnitude > 0) || !std::isfinite(magnitude)) return false;
direction = direction / magnitude;
const auto s = Singleton(direction);
lower = std::numeric_limits<double>::infinity();
for (double xi : {-1., 1.}) {
for (double eta : {-1., 1.}) {
const auto w = Cross(geometry.bi + Interval{eta} * geometry.di,
geometry.ci + Interval{xi} * geometry.di);
const Interval projection = Dot(s, w);
if (!projection.IsFinite() || !(projection.lower > 0)) return false;
lower = std::min(lower, projection.lower);
}
}
const Interval bound = Interval{lower} / Sqrt(NormSquared(s));
lower = bound.lower;
return bound.IsFinite() && lower > 0;
}
} // namespace
Status GeometryFailure(const SourceEntityId& source,
const SourceLocation& location, const char* code,
const char* message) {
return Status::Failure(
FailureCategory::kModel,
{{Severity::kError, code, location, "DS4",
source.instance_name + ":" + source.source_label_text, message}});
}
Result<Geometry> BuildGeometry(const std::array<Vector3, 4>& coordinates,
const SourceEntityId& source,
const SourceLocation& location) {
double largest = 0;
for (std::size_t i = 0; i < 4; ++i) {
if (!coordinates[i].IsFinite()) {
return Result<Geometry>::Failure(
GeometryFailure(source, location, "invalid-thermal-shell-geometry",
"Coordinates must be finite."));
}
for (std::size_t j = 0; j < i; ++j) {
if (coordinates[i] == coordinates[j]) {
return Result<Geometry>::Failure(
GeometryFailure(source, location, "invalid-thermal-shell-geometry",
"Patch has repeated coordinates."));
}
}
for (double component : coordinates[i].Components()) {
largest = std::max(largest, std::abs(component));
}
}
int coordinate_exponent = 0;
std::frexp(largest, &coordinate_exponent);
std::array<Vector3, 4> offsets{};
std::array<IntervalVector, 4> intervals{};
double length = 0;
// Scaling before subtraction prevents overflow even for opposite huge inputs.
for (std::size_t i = 1; i < 4; ++i) {
std::array<double, 3> offset{};
for (std::size_t j = 0; j < 3; ++j) {
offset[j] = std::ldexp(coordinates[i][j], -coordinate_exponent) -
std::ldexp(coordinates[0][j], -coordinate_exponent);
intervals[i][j] =
Scale(Interval{coordinates[i][j]}, -coordinate_exponent) -
Scale(Interval{coordinates[0][j]}, -coordinate_exponent);
length = std::max(length, std::abs(offset[j]));
}
offsets[i] = Vector3{offset};
}
int offset_exponent = 0;
std::frexp(length, &offset_exponent);
for (std::size_t i = 1; i < 4; ++i) {
std::array<double, 3> offset{};
for (std::size_t j = 0; j < 3; ++j) {
offset[j] = std::ldexp(offsets[i][j], -offset_exponent);
intervals[i][j] = Scale(intervals[i][j], -offset_exponent);
}
offsets[i] = Vector3{offset};
}
Geometry geometry{};
geometry.length_exponent = coordinate_exponent + offset_exponent;
geometry.b = .25 * (offsets[1] + offsets[2] - offsets[3]);
geometry.c = .25 * (offsets[2] + offsets[3] - offsets[1]);
geometry.d = .25 * (offsets[2] - offsets[1] - offsets[3]);
geometry.bi = Interval{.25} * (intervals[1] + intervals[2] - intervals[3]);
geometry.ci = Interval{.25} * (intervals[2] + intervals[3] - intervals[1]);
geometry.di = Interval{.25} * (intervals[2] - intervals[1] - intervals[3]);
const Vector3 w0 = geometry.b.Cross(geometry.c);
const Vector3 u = geometry.b.Cross(geometry.d);
const Vector3 v = geometry.d.Cross(geometry.c);
std::vector<Vector3> candidates;
candidates.reserve(10);
for (double xi : {-1., 1.}) {
for (double eta : {-1., 1.}) candidates.push_back(w0 + xi * u + eta * v);
}
// Projection here is the exact constrained-edge minimizer, not a geometry
// clamp.
for (double edge : {-1., 1.}) {
if (v.Dot(v) > 0) {
const double eta = std::clamp(-v.Dot(w0 + edge * u) / v.Dot(v), -1., 1.);
candidates.push_back(w0 + edge * u + eta * v);
}
if (u.Dot(u) > 0) {
const double xi = std::clamp(-u.Dot(w0 + edge * v) / u.Dot(u), -1., 1.);
candidates.push_back(w0 + xi * u + edge * v);
}
}
const double uu = u.Dot(u);
const double vv = v.Dot(v);
const double uv = u.Dot(v);
const double determinant = uu * vv - uv * uv;
if (determinant > 0 && std::isfinite(determinant)) {
const double xi = (uv * v.Dot(w0) - vv * u.Dot(w0)) / determinant;
const double eta = (uv * u.Dot(w0) - uu * v.Dot(w0)) / determinant;
if (std::abs(xi) <= 1 && std::abs(eta) <= 1) {
candidates.push_back(w0 + xi * u + eta * v);
}
}
// The center is also useful for affine or rank-one normal images.
candidates.push_back(w0);
for (const auto& candidate : candidates) {
if (Certify(geometry, candidate, geometry.scaled_jacobian_lower)) {
return Result<Geometry>::Success(geometry);
}
}
return Result<Geometry>::Failure(
GeometryFailure(source, location, "uncertain-thermal-shell-geometry",
"No strictly positive whole-patch interval bound was "
"certified (lower <= 0)."));
}
Result<SurfacePoint> EvaluateSurface(const Geometry& geometry, double xi,
double eta, Interval xi_interval,
Interval eta_interval,
const SourceEntityId& source,
const SourceLocation& location) {
const Vector3 a1 = geometry.b + eta * geometry.d;
const Vector3 a2 = geometry.c + xi * geometry.d;
const auto a1i = geometry.bi + eta_interval * geometry.di;
const auto a2i = geometry.ci + xi_interval * geometry.di;
const Vector3 w = a1.Cross(a2);
const auto wi = Cross(a1i, a2i);
const double jacobian = w.Norm();
const Interval determinant_interval = NormSquared(wi);
const double determinant = w.Dot(w);
// |a1 x a2|^2 is the Gram determinant identity, avoiding subtraction of
// nearly equal g11*g22 and g12*g12. This is still the actual-point metric.
const Interval inverse11 = Dot(a2i, a2i) / determinant_interval;
const Interval inverse12 =
(Interval{0} - Dot(a1i, a2i)) / determinant_interval;
const Interval inverse22 = Dot(a1i, a1i) / determinant_interval;
if (!(determinant_interval.lower > 0) || !inverse11.IsFinite() ||
!inverse12.IsFinite() || !inverse22.IsFinite() || !(jacobian > 0) ||
!std::isfinite(determinant) || determinant <= 0 ||
!Scale(inverse11, -2 * geometry.length_exponent).IsFinite() ||
!Scale(inverse12, -2 * geometry.length_exponent).IsFinite() ||
!Scale(inverse22, -2 * geometry.length_exponent).IsFinite() ||
!Scale(Dot(a1i, a1i), 2 * geometry.length_exponent).IsFinite() ||
!Scale(Dot(a2i, a2i), 2 * geometry.length_exponent).IsFinite()) {
return Result<SurfacePoint>::Failure(GeometryFailure(
source, location, "uncertain-thermal-shell-metric",
"Metric inverse enclosure is not finite or excludes no zero divisor."));
}
const Vector3 reciprocal1 = a2.Cross(w) / determinant;
const Vector3 reciprocal2 = w.Cross(a1) / determinant;
const auto reciprocal1i =
(Interval{1} / determinant_interval) * Cross(a2i, wi);
const auto reciprocal2i =
(Interval{1} / determinant_interval) * Cross(wi, a1i);
SurfacePoint point{};
point.jacobian = std::ldexp(jacobian, 2 * geometry.length_exponent);
point.jacobian_interval =
Scale(Sqrt(determinant_interval), 2 * geometry.length_exponent);
point.axes[0] = a1 / a1.Norm();
point.axes[2] = w / jacobian;
point.axes[1] = point.axes[2].Cross(point.axes[0]);
constexpr std::array<double, 4> kXi{{-1., 1., 1., -1.}};
constexpr std::array<double, 4> kEta{{-1., -1., 1., 1.}};
for (std::size_t i = 0; i < 4; ++i) {
point.shape[i] = .25 * (1 + kXi[i] * xi) * (1 + kEta[i] * eta);
point.shape_interval[i] = Interval{.25} *
(Interval{1} + Interval{kXi[i]} * xi_interval) *
(Interval{1} + Interval{kEta[i]} * eta_interval);
const double dx = .25 * kXi[i] * (1 + kEta[i] * eta);
const double dy = .25 * kEta[i] * (1 + kXi[i] * xi);
const Interval dxi = Interval{.25 * kXi[i]} *
(Interval{1} + Interval{kEta[i]} * eta_interval);
const Interval dyi = Interval{.25 * kEta[i]} *
(Interval{1} + Interval{kXi[i]} * xi_interval);
const Vector3 gradient = dx * reciprocal1 + dy * reciprocal2;
const auto gradient_interval = dxi * reciprocal1i + dyi * reciprocal2i;
std::array<double, 3> components{};
for (std::size_t j = 0; j < 3; ++j) {
components[j] = std::ldexp(gradient[j], -geometry.length_exponent);
point.gradient_interval[i][j] =
Scale(gradient_interval[j], -geometry.length_exponent);
}
point.gradient[i] = Vector3{components};
if (!point.gradient[i].IsFinite() ||
!IsFinite(point.gradient_interval[i])) {
return Result<SurfacePoint>::Failure(
GeometryFailure(source, location, "uncertain-thermal-shell-metric",
"Surface gradient enclosure is not finite."));
}
}
if (!(point.jacobian > 0) || !std::isfinite(point.jacobian) ||
!point.jacobian_interval.IsFinite() ||
!(point.jacobian_interval.lower > 0) || !point.axes[0].IsFinite() ||
!point.axes[1].IsFinite() || !point.axes[2].IsFinite()) {
return Result<SurfacePoint>::Failure(GeometryFailure(
source, location, "uncertain-thermal-shell-metric",
"Surface measure or frame is not finite and positive."));
}
return Result<SurfacePoint>::Success(point);
}
} // namespace thermal_internal
namespace {
using Edge = std::pair<EntityIndex, EntityIndex>;
/// @brief Forms a deterministic undirected source edge key.
Edge EdgeKey(EntityIndex first, EntityIndex second) {
return std::minmax(first, second);
}
/// @brief Rejects possible open-edge contact only for an actual source
/// candidate.
Status CheckPartialEdge(const ModelDefinition& definition, EntityIndex p,
EntityIndex q, EntityIndex v,
const Ds4ThermalElementDefinition& owner) {
using namespace thermal_internal;
const Vector3 x{definition.nodes[p].coordinates};
const Vector3 y{definition.nodes[q].coordinates};
const Vector3 z{definition.nodes[v].coordinates};
double largest = 0;
for (std::size_t j = 0; j < 3; ++j) {
largest =
std::max({largest, std::abs(x[j]), std::abs(y[j]), std::abs(z[j])});
}
int exponent = 0;
std::frexp(largest, &exponent);
IntervalVector a;
IntervalVector b;
std::size_t axis = 0;
double best = 0;
for (std::size_t j = 0; j < 3; ++j) {
a[j] = Scale(Interval{y[j]}, -exponent) - Scale(Interval{x[j]}, -exponent);
b[j] = Scale(Interval{z[j]}, -exponent) - Scale(Interval{x[j]}, -exponent);
const double lower = a[j].ContainsZero() ? 0
: std::min(std::abs(a[j].lower),
std::abs(a[j].upper));
if (lower > best) {
best = lower;
axis = j;
}
}
if (best > 0) {
const Interval lambda = b[axis] / a[axis];
if (lambda.upper < 0 || lambda.lower > 1) return Status::Ok();
for (std::size_t j = 0; j < 3; ++j) {
if (!(b[j] - lambda * a[j]).ContainsZero()) return Status::Ok();
}
}
return GeometryFailure(owner.source_id, owner.location,
"uncertain-thermal-shell-connection",
"Source-sharing coarse/partial edges have unresolved "
"or nonconforming open-edge contact.");
}
} // namespace
Status ValidateThermalShellMesh(const ModelDefinition& definition) {
using namespace thermal_internal;
struct Incidence {
EntityIndex first;
EntityIndex second;
std::size_t element;
};
std::map<Edge, std::vector<Incidence>> edges;
std::map<EntityIndex, std::map<EntityIndex, std::vector<EntityIndex>>> links;
std::set<std::array<EntityIndex, 4>> patches;
std::map<std::pair<std::string, std::int64_t>, EntityIndex> source_nodes;
for (std::size_t index = 0; index < definition.thermal_elements.size();
++index) {
const auto& element = definition.thermal_elements[index];
for (const EntityIndex node : element.node_indices) {
const auto& source = definition.nodes[node].source_id;
const auto inserted = source_nodes.emplace(
std::make_pair(source.instance_name, source.source_label), node);
if (!inserted.second && inserted.first->second != node) {
return GeometryFailure(
element.source_id, element.location,
"invalid-thermal-shell-topology",
"One source node identity has multiple indices.");
}
}
auto sorted = element.node_indices;
std::sort(sorted.begin(), sorted.end());
if (std::adjacent_find(sorted.begin(), sorted.end()) != sorted.end() ||
!patches.insert(sorted).second) {
return GeometryFailure(element.source_id, element.location,
"invalid-thermal-shell-topology",
"Repeated node or duplicate element patch.");
}
std::array<Vector3, 4> coordinates{};
for (std::size_t i = 0; i < 4; ++i)
coordinates[i] =
Vector3{definition.nodes[element.node_indices[i]].coordinates};
const auto geometry =
BuildGeometry(coordinates, element.source_id, element.location);
if (!geometry.HasValue()) return geometry.GetStatus();
// Domain never publishes geometry that fails at any kernel/recovery point.
const double gauss = std::sqrt(3. / 5.);
for (double xi : {-gauss, 0., gauss}) {
for (double eta : {-gauss, 0., gauss}) {
const auto point = EvaluateSurface(
geometry.Value(), xi, eta, Interval{Down(xi), Up(xi)},
Interval{Down(eta), Up(eta)}, element.source_id, element.location);
if (!point.HasValue()) return point.GetStatus();
}
}
const double recovery = 1 / std::sqrt(3.);
for (double xi : {-recovery, recovery}) {
for (double eta : {-recovery, recovery}) {
const auto point = EvaluateSurface(
geometry.Value(), xi, eta, Interval{Down(xi), Up(xi)},
Interval{Down(eta), Up(eta)}, element.source_id, element.location);
if (!point.HasValue()) return point.GetStatus();
}
}
for (std::size_t i = 0; i < 4; ++i) {
const EntityIndex node = element.node_indices[i];
const EntityIndex next = element.node_indices[(i + 1) % 4];
const EntityIndex previous = element.node_indices[(i + 3) % 4];
edges[EdgeKey(node, next)].push_back({node, next, index});
links[node][previous].push_back(next);
links[node][next].push_back(previous);
}
}
for (const auto& item : edges) {
const auto& incidence = item.second;
if (incidence.size() > 2 ||
(incidence.size() == 2 && incidence[0].first == incidence[1].first)) {
const auto& element =
definition.thermal_elements[incidence.back().element];
return GeometryFailure(
element.source_id, element.location, "invalid-thermal-shell-topology",
"Shared edge must have at most two opposite incidences.");
}
}
for (const auto& vertex : links) {
const auto& graph = vertex.second;
std::set<EntityIndex> visited;
std::vector<EntityIndex> pending{graph.begin()->first};
std::size_t ends = 0;
bool invalid = false;
for (const auto& item : graph) {
const auto& adjacent = item.second;
if (adjacent.size() == 1) ++ends;
if (adjacent.size() > 2 ||
(adjacent.size() == 2 && adjacent[0] == adjacent[1]))
invalid = true;
}
while (!pending.empty()) {
const auto node = pending.back();
pending.pop_back();
if (!visited.insert(node).second) continue;
for (const auto next : graph.at(node)) pending.push_back(next);
}
if (invalid || visited.size() != graph.size() || (ends != 0 && ends != 2)) {
const auto& incidence =
edges.at(EdgeKey(vertex.first, graph.begin()->first))[0];
const auto& element = definition.thermal_elements[incidence.element];
return GeometryFailure(element.source_id, element.location,
"invalid-thermal-shell-topology",
"Vertex link is not one path or cycle.");
}
}
// Enumerate only incident SOURCE edges, never all mesh coordinates vs edges.
std::map<EntityIndex, std::set<EntityIndex>> neighbors;
for (const auto& item : edges) {
neighbors[item.first.first].insert(item.first.second);
neighbors[item.first.second].insert(item.first.first);
}
for (const auto& item : edges) {
for (const auto endpoint : {item.first.first, item.first.second}) {
const EntityIndex other =
endpoint == item.first.first ? item.first.second : item.first.first;
const auto& owner = definition.thermal_elements[item.second[0].element];
for (const auto partial : neighbors[endpoint]) {
if (partial == other) continue;
const auto& instance =
definition.nodes[endpoint].source_id.instance_name;
if (definition.nodes[other].source_id.instance_name != instance ||
definition.nodes[partial].source_id.instance_name != instance)
continue;
const Status status =
CheckPartialEdge(definition, endpoint, other, partial, owner);
if (!status.IsOk()) return status;
}
}
}
return Status::Ok();
}
} // namespace fesa
@@ -0,0 +1,59 @@
#ifndef FESA_ELEMENTS_THERMAL_SHELL_GEOMETRY_H_
#define FESA_ELEMENTS_THERMAL_SHELL_GEOMETRY_H_
#include <array>
#include "fesa/core/status.h"
#include "fesa/math/vector3.h"
#include "thermal_interval.h"
namespace fesa {
struct ModelDefinition;
namespace thermal_internal {
/// @brief Holds translated, power-of-two scaled tangents and their enclosures.
struct Geometry {
Vector3 b;
Vector3 c;
Vector3 d;
IntervalVector bi;
IntervalVector ci;
IntervalVector di;
int length_exponent = 0;
double scaled_jacobian_lower = 0;
};
/// @brief Holds actual-point product metric, gradients and orthonormal columns.
struct SurfacePoint {
std::array<double, 4> shape{};
std::array<Interval, 4> shape_interval{};
std::array<Vector3, 4> gradient{};
std::array<IntervalVector, 4> gradient_interval{};
std::array<Vector3, 3> axes{};
double jacobian = 0;
Interval jacobian_interval;
};
/// @brief Certifies whole-patch rank/injectivity from fixed candidate
/// directions.
Result<Geometry> BuildGeometry(const std::array<Vector3, 4>& coordinates,
const SourceEntityId& source,
const SourceLocation& location);
/// @brief Checks finite metric inverse and gradients at one used surface point.
Result<SurfacePoint> EvaluateSurface(const Geometry& geometry, double xi,
double eta, Interval xi_interval,
Interval eta_interval,
const SourceEntityId& source,
const SourceLocation& location);
/// @brief Builds a geometry failure retaining original source element identity.
Status GeometryFailure(const SourceEntityId& source,
const SourceLocation& location, const char* code,
const char* message);
} // namespace thermal_internal
/// @brief Validates DS4 whole-patch geometry and source-only manifold topology.
/// @pre Node indices and section assignments have been checked by Domain.
Status ValidateThermalShellMesh(const ModelDefinition& definition);
} // namespace fesa
#endif // FESA_ELEMENTS_THERMAL_SHELL_GEOMETRY_H_
+4
View File
@@ -8,6 +8,8 @@
#include <string>
#include <utility>
#include "../elements/thermal_shell_geometry.h"
namespace fesa {
namespace {
@@ -112,6 +114,8 @@ Status ValidateThermalDefinition(const ModelDefinition& definition) {
active_nodes[node] = true;
}
}
const Status geometry_status = ValidateThermalShellMesh(definition);
if (!geometry_status.IsOk()) return geometry_status;
std::map<EntityIndex, std::array<double, 5>> initial_values;
for (const auto& initial : definition.thermal_initial_conditions) {
if (initial.node_index >= active_nodes.size() ||
@@ -0,0 +1,108 @@
#include "fesa/analysis/thermal_time_grid.h"
#include <gtest/gtest.h>
#include <cmath>
#include <limits>
TEST(ThermalTimeGrid, SingleStepUsesPeriodAsActualIncrement) {
const auto grid = fesa::ThermalTimeGrid::Create(2.0, 3.0, 1U);
ASSERT_TRUE(grid.HasValue());
EXPECT_EQ(grid.Value().Count(), 1U);
EXPECT_EQ(grid.Value().Delta(1U), 2.0);
}
TEST(ThermalTimeGrid, PreservesGenuineRemainderOutsideInputCells) {
const auto grid =
fesa::ThermalTimeGrid::Create(std::nextafter(.9, 1.0), .3, 4U);
ASSERT_TRUE(grid.HasValue());
EXPECT_EQ(grid.Value().Count(), 4U);
EXPECT_EQ(grid.Value().Delta(4U), 1.6653345369377348e-16);
}
TEST(ThermalTimeGrid, OriginalSubnormalCellsRespectOpenAndClosedContact) {
const double tiny = std::numeric_limits<double>::denorm_min();
const auto even = fesa::ThermalTimeGrid::Create(20 * tiny, 6 * tiny, 4U);
const auto odd = fesa::ThermalTimeGrid::Create(17 * tiny, 5 * tiny, 4U);
ASSERT_TRUE(even.HasValue());
ASSERT_TRUE(odd.HasValue());
EXPECT_EQ(even.Value().Count(), 3U);
EXPECT_EQ(odd.Value().Count(), 4U);
EXPECT_EQ(odd.Value().Delta(4U), 2 * tiny);
}
TEST(ThermalTimeGrid, DecimalCellsCounterexampleAndScale) {
for (const int exponent : {-1000, 0, 1000}) {
const double period = std::ldexp(.9, exponent);
const double delta = std::ldexp(.3, exponent);
const auto grid = fesa::ThermalTimeGrid::Create(period, delta, 3U);
ASSERT_TRUE(grid.HasValue());
EXPECT_EQ(grid.Value().Count(), 3U);
EXPECT_EQ(grid.Value().Delta(3U), delta);
EXPECT_EQ(grid.Value().Time(3U), period);
}
const auto old_counterexample =
fesa::ThermalTimeGrid::Create(5.351455173733616, .17262758624947144, 31U);
ASSERT_TRUE(old_counterexample.HasValue());
EXPECT_EQ(old_counterexample.Value().Count(), 31U);
EXPECT_EQ(old_counterexample.Value().Delta(31U), .17262758624947144);
EXPECT_FALSE(
fesa::ThermalTimeGrid::Create(5.351455173733616, .17262758624947144, 30U)
.HasValue());
}
TEST(ThermalTimeGrid, BinadeLimitsAndMaximumFinitePreserveOriginalCells) {
const double max = std::numeric_limits<double>::max();
const auto grid = fesa::ThermalTimeGrid::Create(max, max / 3, 3U);
ASSERT_TRUE(grid.HasValue());
EXPECT_EQ(grid.Value().Count(), 3U);
EXPECT_EQ(grid.Value().Delta(3U), max / 3);
const auto upper =
fesa::ThermalTimeGrid::Create(4294967295., 1., 4294967295U);
ASSERT_TRUE(upper.HasValue());
EXPECT_EQ(upper.Value().Count(), 4294967295U);
EXPECT_TRUE(upper.Value().Frame(4294967295U).HasValue());
EXPECT_FALSE(
fesa::ThermalTimeGrid::Create(4294967296., 1., 4294967295U).HasValue());
EXPECT_FALSE(fesa::ThermalTimeGrid::Create(
max, std::numeric_limits<double>::denorm_min(), 4294967295U)
.HasValue());
}
TEST(ThermalTimeGrid, ShortenedIncrementAndCheckedFrames) {
const auto grid = fesa::ThermalTimeGrid::Create(10., 3., 4U);
ASSERT_TRUE(grid.HasValue());
EXPECT_EQ(grid.Value().Count(), 4U);
EXPECT_EQ(grid.Value().Time(0U), 0.);
for (std::uint32_t i = 1; i <= 4; ++i) {
ASSERT_TRUE(grid.Value().Frame(i).HasValue());
EXPECT_EQ(grid.Value().Time(i), i == 4 ? 10. : 3. * i);
EXPECT_EQ(grid.Value().Delta(i), i == 4 ? 1. : 3.);
}
EXPECT_FALSE(grid.Value().Frame(0U).HasValue());
EXPECT_FALSE(grid.Value().Frame(5U).HasValue());
const auto decimals = fesa::ThermalTimeGrid::Create(1., .1);
ASSERT_TRUE(decimals.HasValue());
EXPECT_EQ(decimals.Value().Time(3U), .30000000000000004);
EXPECT_EQ(decimals.Value().Delta(10U), .1);
const double below = std::nextafter(.9, 0.);
const auto close = fesa::ThermalTimeGrid::Create(below, .3, 3U);
const auto short_last =
fesa::ThermalTimeGrid::Create(std::nextafter(below, 0.), .3, 3U);
ASSERT_TRUE(close.HasValue());
ASSERT_TRUE(short_last.HasValue());
EXPECT_EQ(close.Value().Delta(3U), .3);
EXPECT_EQ(short_last.Value().Delta(3U), .2999999999999998);
}
TEST(ThermalTimeGrid, RejectsInvalidControlsBeforeIntegerConversion) {
for (double bad : {0., -1., std::numeric_limits<double>::infinity(),
std::numeric_limits<double>::quiet_NaN()}) {
EXPECT_FALSE(fesa::ThermalTimeGrid::Create(bad, 1.).HasValue());
EXPECT_FALSE(fesa::ThermalTimeGrid::Create(1., bad).HasValue());
}
EXPECT_FALSE(fesa::ThermalTimeGrid::Create(1., 1., 0U).HasValue());
const auto equal = fesa::ThermalTimeGrid::Create(2., 2., 1U);
ASSERT_TRUE(equal.HasValue());
EXPECT_EQ(equal.Value().Delta(1U), 2.);
}
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#include "fesa/elements/thermal_shell.h"
#include <gtest/gtest.h>
#include <algorithm>
#include <array>
#include <cmath>
#include <limits>
#include <numeric>
namespace {
using fesa::Matrix;
using fesa::Vector3;
using Patch = std::array<Vector3, 4>;
const Patch kSquare{{{0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}}};
double Gamma(int operations) {
const double product = operations * std::ldexp(1., -53);
return product / (1 - product);
}
double Norm(const Matrix& matrix) {
double norm = 0;
for (std::size_t i = 0; i < matrix.Rows(); ++i)
for (std::size_t j = 0; j < matrix.Columns(); ++j)
norm = std::hypot(norm, matrix(i, j));
return norm;
}
double Difference(const Matrix& a, const Matrix& b) {
double norm = 0;
for (std::size_t i = 0; i < a.Rows(); ++i)
for (std::size_t j = 0; j < a.Columns(); ++j)
norm = std::hypot(norm, a(i, j) - b(i, j));
return norm;
}
fesa::Result<fesa::ThermalShell> Kernel(const Patch& patch = kSquare,
double h = 2, double k = 1) {
return fesa::ThermalShell::Create({"patch", 19, "0019"}, {{7, 2, 9, 4}},
patch, k, 1, 1, h, {"kernel.inp", 42});
}
struct Oracle {
Matrix c{20, 20};
Matrix k{20, 20};
Matrix pc{20, 20};
Matrix pk{20, 20};
};
// Independently integrated exact rational unit-square matrices, h variable.
// The signed products are kept separate from their absolute contribution sums.
Oracle Rational(double h) {
constexpr int mass[4][4] = {
{4, 2, 1, 2}, {2, 4, 2, 1}, {1, 2, 4, 2}, {2, 1, 2, 4}};
constexpr int stiffness[4][4] = {
{4, -1, -2, -1}, {-1, 4, -1, -2}, {-2, -1, 4, -1}, {-1, -2, -1, 4}};
constexpr int z0[5][5] = {{4, 2, -1, 0, 0},
{2, 16, 2, 0, 0},
{-1, 2, 8, 2, -1},
{0, 0, 2, 16, 2},
{0, 0, -1, 2, 4}};
constexpr int z1[5][5] = {{7, -8, 1, 0, 0},
{-8, 16, -8, 0, 0},
{1, -8, 14, -8, 1},
{0, 0, -8, 16, -8},
{0, 0, 1, -8, 7}};
Oracle result;
for (std::size_t p = 0; p < 20; ++p)
for (std::size_t q = 0; q < 20; ++q) {
const auto i = p / 5, j = q / 5, a = p % 5, b = q % 5;
result.c(p, q) = h * mass[i][j] * z0[a][b] / 2160.;
const double tangential = h * stiffness[i][j] * z0[a][b] / 360.;
const double normal = mass[i][j] * z1[a][b] / (54. * h);
result.k(p, q) = tangential + normal;
result.pc(p, q) = std::abs(result.c(p, q));
const double sx[4] = {-1, 1, 1, -1}, sy[4] = {-1, -1, 1, 1};
const double ps = (sx[i] == sx[j] ? 1. / 3 : 1. / 6) +
(sy[i] == sy[j] ? 1. / 3 : 1. / 6);
result.pk(p, q) = h * ps * std::abs(z0[a][b]) / 60 + std::abs(normal);
}
return result;
}
// Independent 54-point B^T B/H^T H oracle: no exact-Z or production helper.
Oracle Direct54(const Patch& coordinates, double h) {
Oracle result;
const double g = std::sqrt(.6);
const std::array<double, 3> gauss{{-g, 0, g}},
weight{{5. / 9, 8. / 9, 5. / 9}};
constexpr double sx[4] = {-1, 1, 1, -1}, sy[4] = {-1, -1, 1, 1};
for (std::size_t ix = 0; ix < 3; ++ix)
for (std::size_t iy = 0; iy < 3; ++iy) {
std::array<double, 4> n{}, dx{}, dy{};
Vector3 a1, a2;
for (std::size_t i = 0; i < 4; ++i) {
n[i] = (1 + sx[i] * gauss[ix]) * (1 + sy[i] * gauss[iy]) / 4;
dx[i] = sx[i] * (1 + sy[i] * gauss[iy]) / 4;
dy[i] = sy[i] * (1 + sx[i] * gauss[ix]) / 4;
a1 = a1 + dx[i] * coordinates[i];
a2 = a2 + dy[i] * coordinates[i];
}
const double aa = a1.Dot(a1), bb = a2.Dot(a2), ab = a1.Dot(a2);
const double det = aa * bb - ab * ab;
const Vector3 normal = a1.Cross(a2) / std::sqrt(det);
const Vector3 reciprocal1 = (bb * a1 - ab * a2) / det;
const Vector3 reciprocal2 = (aa * a2 - ab * a1) / det;
for (std::size_t segment = 0; segment < 2; ++segment)
for (std::size_t iz = 0; iz < 3; ++iz) {
const double s = gauss[iz];
const std::array<double, 3> l{
{s * (s - 1) / 2, 1 - s * s, s * (s + 1) / 2}};
const std::array<double, 3> dl{{2 * s - 1, -4 * s, 2 * s + 1}};
std::array<double, 20> shape{};
std::array<Vector3, 20> gradient{};
const double w =
weight[ix] * weight[iy] * weight[iz] * std::sqrt(det) * h / 4;
for (std::size_t i = 0; i < 4; ++i)
for (std::size_t a = 0; a < 3; ++a) {
const auto p = 5 * i + 2 * segment + a;
shape[p] = n[i] * l[a];
gradient[p] = l[a] * (dx[i] * reciprocal1 + dy[i] * reciprocal2) +
(2 * n[i] * dl[a] / h) * normal;
}
for (std::size_t p = 0; p < 20; ++p)
for (std::size_t q = 0; q < 20; ++q) {
const double c = shape[p] * shape[q] * w;
const double k = gradient[p].Dot(gradient[q]) * w;
result.c(p, q) += c;
result.k(p, q) += k;
result.pc(p, q) += std::abs(c);
// Component products, not absolute signed dot products.
for (std::size_t axis = 0; axis < 3; ++axis)
result.pk(p, q) +=
std::abs(gradient[p][axis] * gradient[q][axis] * w);
}
}
}
return result;
}
// Direct recovery operator and absolute propagation scale, independent of the
// production cache. Rows preserve the two one-sided center derivatives.
struct FluxOracle {
std::array<Vector3, 24> value{};
std::array<double, 24> scale{};
};
FluxOracle Flux(const Patch& patch, double h, const std::array<double, 20>& t) {
FluxOracle result;
const double g = 1 / std::sqrt(3.);
const double sx[4] = {-1, 1, 1, -1}, sy[4] = {-1, -1, 1, 1};
for (std::size_t ip = 0; ip < 4; ++ip) {
std::array<double, 4> n{}, dx{}, dy{};
Vector3 a1, a2;
for (std::size_t i = 0; i < 4; ++i) {
n[i] = (1 + sx[i] * sx[ip] * g) * (1 + sy[i] * sy[ip] * g) / 4;
dx[i] = sx[i] * (1 + sy[i] * sy[ip] * g) / 4;
dy[i] = sy[i] * (1 + sx[i] * sx[ip] * g) / 4;
a1 = a1 + dx[i] * patch[i];
a2 = a2 + dy[i] * patch[i];
}
const double aa = a1.Dot(a1), bb = a2.Dot(a2), ab = a1.Dot(a2),
det = aa * bb - ab * ab;
const Vector3 normal = a1.Cross(a2) / std::sqrt(det);
const Vector3 r1 = (bb * a1 - ab * a2) / det,
r2 = (aa * a2 - ab * a1) / det;
for (std::size_t trace = 0; trace < 6; ++trace) {
const double x = static_cast<double>(trace % 3) - 1;
const double l[3] = {x * (x - 1) / 2, 1 - x * x, x * (x + 1) / 2};
const double dl[3] = {2 * x - 1, -4 * x, 2 * x + 1};
const auto row = 6 * ip + trace;
for (std::size_t i = 0; i < 4; ++i)
for (std::size_t a = 0; a < 3; ++a) {
const auto p = 5 * i + (trace < 3 ? 0 : 2) + a;
const Vector3 first = (l[a] * dx[i]) * r1;
const Vector3 second = (l[a] * dy[i]) * r2;
const Vector3 third = (2 * n[i] * dl[a] / h) * normal;
result.value[row] =
result.value[row] - t[p] * (first + second + third);
result.scale[row] +=
std::abs(t[p]) * (first.Norm() + second.Norm() + third.Norm());
}
}
}
return result;
}
// Jacobi orthogonal diagonalization plus a posteriori residual and
// orthogonality budget. No guessed eigenvalue epsilon is used for the rank
// decision.
std::pair<double, double> EigenExtrema(const Matrix& original,
double& backward) {
Matrix a = original;
const auto n = a.Rows();
Matrix v{n, n};
for (std::size_t i = 0; i < n; ++i) v(i, i) = 1;
for (int sweep = 0; sweep < 100; ++sweep) {
for (std::size_t p = 0; p < n; ++p)
for (std::size_t q = p + 1; q < n; ++q) {
if (a(p, q) == 0) continue;
const double tau = (a(q, q) - a(p, p)) / (2 * a(p, q));
const double t =
std::copysign(1., tau) / (std::abs(tau) + std::hypot(1., tau));
const double c = 1 / std::hypot(1., t), s = t * c;
const double off = a(p, q);
a(p, p) -= t * off;
a(q, q) += t * off;
a(p, q) = a(q, p) = 0;
for (std::size_t j = 0; j < n; ++j) {
if (j != p && j != q) {
const double x = a(j, p), y = a(j, q);
a(j, p) = a(p, j) = c * x - s * y;
a(j, q) = a(q, j) = s * x + c * y;
}
const double x = v(j, p), y = v(j, q);
v(j, p) = c * x - s * y;
v(j, q) = s * x + c * y;
}
}
}
double residual = 0, orthogonality = 0;
for (std::size_t i = 0; i < n; ++i)
for (std::size_t j = 0; j < n; ++j) {
double av = 0, vv = 0, absolute = 0;
for (std::size_t k = 0; k < n; ++k) {
av += original(i, k) * v(k, j);
absolute += std::abs(original(i, k) * v(k, j));
vv += v(k, i) * v(k, j);
}
residual = std::hypot(residual,
std::abs(av - v(i, j) * a(j, j)) +
Gamma(2 * static_cast<int>(n) + 2) *
(absolute + std::abs(v(i, j) * a(j, j))));
orthogonality =
std::hypot(orthogonality, std::abs(vv - (i == j ? 1. : 0.)) +
Gamma(2 * static_cast<int>(n) + 2));
}
EXPECT_LT(orthogonality, 1.);
backward =
(residual + 2 * Norm(original) * orthogonality) / (1 - orthogonality);
double low = a(0, 0), high = a(0, 0);
for (std::size_t i = 1; i < n; ++i) {
low = std::min(low, a(i, i));
high = std::max(high, a(i, i));
}
return {low, high};
}
} // namespace
TEST(ThermalShell, RationalMatricesSymmetryAndConstantModeUseFixedBudgets) {
const auto created = Kernel();
ASSERT_TRUE(created.HasValue());
const auto& kernel = created.Value();
const auto exact = Rational(2);
const double ec = Gamma(4096) * Norm(exact.pc),
ek = Gamma(4096) * Norm(exact.pk);
EXPECT_LE(Difference(kernel.Capacity(), exact.c), ec);
EXPECT_LE(Difference(kernel.Conductivity(), exact.k), ek);
double cs = 0, ks = 0, null = 0, total = 0;
for (std::size_t i = 0; i < 20; ++i) {
double row = 0;
for (std::size_t j = 0; j < 20; ++j) {
cs = std::hypot(cs, kernel.Capacity()(i, j) - kernel.Capacity()(j, i));
ks = std::hypot(
ks, kernel.Conductivity()(i, j) - kernel.Conductivity()(j, i));
row += kernel.Conductivity()(i, j);
total += kernel.Capacity()(i, j);
}
null = std::hypot(null, row);
}
EXPECT_LE(cs, 2 * ec);
EXPECT_LE(ks, 2 * ek);
EXPECT_LE(null, std::sqrt(20.) * ek);
EXPECT_LE(std::abs(total - 2), 20 * ec);
EXPECT_EQ(kernel.SourceId().source_label_text, "0019");
EXPECT_EQ(kernel.NodeIndices(),
(std::array<fesa::EntityIndex, 4>{{7, 2, 9, 4}}));
}
TEST(ThermalShell, CapacityIsPositiveAndConductionHasExactlyOneNullMode) {
const auto created = Kernel();
ASSERT_TRUE(created.HasValue());
const auto exact = Rational(2);
double backward = 0;
const auto capacity = EigenExtrema(created.Value().Capacity(), backward);
EXPECT_GT(capacity.first, Gamma(4096) * Norm(exact.pc) + backward);
const auto conduction =
EigenExtrema(created.Value().Conductivity(), backward);
EXPECT_LE(std::abs(conduction.first),
Gamma(4096) * Norm(exact.pk) + backward);
// Helmert columns form an independent orthonormal basis of 1-perp.
Matrix basis{20, 19};
for (std::size_t j = 0; j < 19; ++j) {
const double norm = std::sqrt(static_cast<double>((j + 1) * (j + 2)));
for (std::size_t i = 0; i <= j; ++i) basis(i, j) = 1 / norm;
basis(j + 1, j) = -static_cast<double>(j + 1) / norm;
}
Matrix restricted{19, 19};
for (std::size_t i = 0; i < 19; ++i)
for (std::size_t j = 0; j < 19; ++j)
for (std::size_t p = 0; p < 20; ++p)
for (std::size_t q = 0; q < 20; ++q)
restricted(i, j) +=
basis(p, i) * created.Value().Conductivity()(p, q) * basis(q, j);
const auto positive = EigenExtrema(restricted, backward);
const double projection_budget = Gamma(8192) * Norm(exact.pk) * 20;
EXPECT_GT(positive.first,
Gamma(4096) * Norm(exact.pk) + backward + projection_budget);
}
TEST(ThermalShell,
Direct54MatchesSeparatedOperatorsOnActualThreeDimensionalPatches) {
const std::array<Patch, 5> patches{
{kSquare,
{{{0, 0, 0}, {2, 0, 0}, {1.5, 1, 0}, {0, 1, 0}}},
{{{-1, -1, .1}, {1, -1, -.1}, {1, 1, .1}, {-1, 1, -.1}}},
{{{-1, -1, .5}, {1, -1, -.5}, {1, 1, .5}, {-1, 1, -.5}}},
{{{-1, -1, 2}, {1, -1, -2}, {1, 1, 2}, {-1, 1, -2}}}}};
for (const auto& patch : patches) {
const auto created = Kernel(patch);
ASSERT_TRUE(created.HasValue());
const auto direct = Direct54(patch, 2);
const auto& kernel = created.Value();
// General-geometry separation error is the propagated interval enclosure;
// direct 54's independent arithmetic has the prescribed gamma8192 budget.
EXPECT_LE(Difference(kernel.Capacity(), direct.c),
Norm(kernel.CapacityError()) + Gamma(8192) * Norm(direct.pc));
EXPECT_LE(Difference(kernel.Conductivity(), direct.k),
Norm(kernel.ConductivityError()) + Gamma(8192) * Norm(direct.pk));
}
}
TEST(ThermalShell, ThicknessScalingPreservesBothConductionTermsAndCapacity) {
for (double h : {.5, 1., 2.}) {
const auto created = Kernel(kSquare, h);
ASSERT_TRUE(created.HasValue());
const auto exact = Rational(h);
EXPECT_LE(Difference(created.Value().Capacity(), exact.c),
Gamma(4096) * Norm(exact.pc));
EXPECT_LE(Difference(created.Value().Conductivity(), exact.k),
Gamma(4096) * Norm(exact.pk));
}
}
TEST(ThermalShell, AffineLinearFluxFramesAndSeparateMidsurfaceTraces) {
const auto created = Kernel();
ASSERT_TRUE(created.HasValue());
std::array<double, 20> temperature{};
for (std::size_t i = 0; i < 4; ++i)
for (std::size_t a = 0; a < 5; ++a)
temperature[5 * i + a] =
2 + 3 * kSquare[i].X() - 2 * kSquare[i].Y() + 4 * (-1 + .5 * a);
const auto recovery = created.Value().Recover(temperature);
ASSERT_TRUE(recovery.HasValue());
const auto linear_scale = Flux(kSquare, 2, temperature);
for (std::size_t row = 0; row < 24; ++row)
EXPECT_LE(
(recovery.Value().global_flux[row] - Vector3{-3, 2, -4}).Norm(),
Gamma(2048) * (linear_scale.scale[row] + Vector3{3, -2, 4}.Norm()));
for (const auto& frame : recovery.Value().frames) {
for (std::size_t i = 0; i < 3; ++i)
for (std::size_t j = 0; j < 3; ++j)
EXPECT_NEAR(frame[i].Dot(frame[j]), i == j ? 1. : 0., Gamma(2048));
EXPECT_NEAR(frame[0].Cross(frame[1]).Dot(frame[2]), 1., Gamma(2048));
}
for (std::size_t i = 0; i < 4; ++i)
for (std::size_t a = 0; a < 5; ++a)
temperature[5 * i + a] = a < 3 ? 0. : static_cast<double>(a - 2);
const auto traces = created.Value().Recover(temperature);
ASSERT_TRUE(traces.HasValue());
for (std::size_t ip = 0; ip < 4; ++ip) {
EXPECT_EQ(traces.Value().global_flux[6 * ip + 2].Z(), 0.);
EXPECT_NEAR(traces.Value().global_flux[6 * ip + 3].Z(), -2.,
Gamma(2048) * 2);
}
temperature.fill(2);
const auto constant = created.Value().Recover(temperature);
ASSERT_TRUE(constant.HasValue());
const auto constant_scale = Flux(kSquare, 2, temperature);
for (std::size_t row = 0; row < 24; ++row)
EXPECT_LE(constant.Value().global_flux[row].Norm(),
Gamma(2048) * constant_scale.scale[row]);
}
TEST(ThermalShell, TranslationRotationAndReversedNormalPreservePhysicalFlux) {
const auto base = Kernel();
ASSERT_TRUE(base.HasValue());
Patch translated = kSquare, rotated = kSquare, reversed{};
const auto rotate = [](Vector3 p) { return Vector3{p.Z(), p.X(), p.Y()}; };
for (std::size_t i = 0; i < 4; ++i) {
translated[i] = kSquare[i] + Vector3{1048576, -1048576, 1048576};
rotated[i] = rotate(kSquare[i]);
reversed[i] = kSquare[(4 - i) % 4];
}
const auto moved = Kernel(translated), turned = Kernel(rotated),
flipped = Kernel(reversed);
ASSERT_TRUE(moved.HasValue());
ASSERT_TRUE(turned.HasValue());
ASSERT_TRUE(flipped.HasValue());
EXPECT_LE(
Difference(base.Value().Capacity(), moved.Value().Capacity()),
Norm(base.Value().CapacityError()) + Norm(moved.Value().CapacityError()));
EXPECT_LE(
Difference(base.Value().Conductivity(), turned.Value().Conductivity()),
Norm(base.Value().ConductivityError()) +
Norm(turned.Value().ConductivityError()));
std::array<double, 20> temperature{}, reverse_temperature{};
for (std::size_t i = 0; i < 4; ++i)
for (std::size_t a = 0; a < 5; ++a) {
temperature[5 * i + a] =
2 + 3 * kSquare[i].X() - 2 * kSquare[i].Y() + 4 * (-1 + .5 * a);
reverse_temperature[5 * i + a] =
2 + 3 * reversed[i].X() - 2 * reversed[i].Y() - 4 * (-1 + .5 * a);
}
const auto flux = turned.Value().Recover(temperature),
reverse = flipped.Value().Recover(reverse_temperature);
ASSERT_TRUE(flux.HasValue());
ASSERT_TRUE(reverse.HasValue());
const auto turn_scale = Flux(rotated, 2, temperature);
const auto reverse_scale = Flux(reversed, 2, reverse_temperature);
for (std::size_t row = 0; row < 24; ++row) {
EXPECT_LE((flux.Value().global_flux[row] - rotate({-3, 2, -4})).Norm(),
Gamma(2048) * (turn_scale.scale[row] + Vector3{3, -2, 4}.Norm()));
EXPECT_LE(
(reverse.Value().global_flux[row] - Vector3{-3, 2, -4}).Norm(),
Gamma(2048) * (reverse_scale.scale[row] + Vector3{3, -2, 4}.Norm()));
}
}
TEST(ThermalShell, CheckedCreationAndRecoveryRetainSourceAndRejectNonfinite) {
for (double bad : {0., -1., std::numeric_limits<double>::infinity(),
std::numeric_limits<double>::quiet_NaN()}) {
EXPECT_FALSE(Kernel(kSquare, bad).HasValue());
EXPECT_FALSE(Kernel(kSquare, 2, bad).HasValue());
}
const auto created = Kernel();
ASSERT_TRUE(created.HasValue());
std::array<double, 20> temperature{};
temperature[3] = std::numeric_limits<double>::quiet_NaN();
const auto bad = created.Value().Recover(temperature);
ASSERT_FALSE(bad.HasValue());
EXPECT_EQ(bad.GetStatus().Diagnostics()[0].entity_identity, "patch:0019");
EXPECT_EQ(bad.GetStatus().Diagnostics()[0].location.line, 42U);
temperature.fill(std::numeric_limits<double>::max());
temperature[0] = -temperature[0];
EXPECT_FALSE(created.Value().Recover(temperature).HasValue());
}
TEST(ThermalShell, GeneralWarpedFluxUsesActualReciprocalTangentsAndTraceOrder) {
const Patch saddle{{{-1, -1, 2}, {1, -1, -2}, {1, 1, 2}, {-1, 1, -2}}};
const auto created = Kernel(saddle, 1);
ASSERT_TRUE(created.HasValue());
std::array<double, 20> temperature{};
for (std::size_t p = 0; p < 20; ++p)
temperature[p] = static_cast<double>((p * 7) % 11) - 4;
const auto actual = created.Value().Recover(temperature);
ASSERT_TRUE(actual.HasValue());
const auto expected = Flux(saddle, 1, temperature);
for (std::size_t row = 0; row < 24; ++row)
EXPECT_LE((actual.Value().global_flux[row] - expected.value[row]).Norm(),
2 * Gamma(2048) * expected.scale[row]);
// Local normals vary around this saddle; recovery must retain those frames.
EXPECT_GT((actual.Value().frames[0][2] - actual.Value().frames[1][2]).Norm(),
1.);
}
TEST(ThermalShell, PowerOfTwoCoordinateScalingPreservesDimensionedOperators) {
for (int exponent : {-200, 200}) {
Patch patch = kSquare;
const double scale = std::ldexp(1., exponent);
for (auto& point : patch) point = scale * point;
const auto created = Kernel(patch, 2);
ASSERT_TRUE(created.HasValue());
const auto unit = Rational(2);
const auto very_thick = Rational(2 / scale);
// Area multiplies C by s^2; surface conduction is invariant, while the
// normal term multiplies by s^2. Equivalent expression uses h/s and k*s.
Matrix c{20, 20}, k{20, 20};
for (std::size_t p = 0; p < 20; ++p)
for (std::size_t q = 0; q < 20; ++q) {
c(p, q) = std::ldexp(unit.c(p, q), 2 * exponent);
k(p, q) = scale * very_thick.k(p, q);
}
EXPECT_LE(Difference(created.Value().Capacity(), c),
Norm(created.Value().CapacityError()) + Gamma(4096) * Norm(c));
EXPECT_LE(
Difference(created.Value().Conductivity(), k),
Norm(created.Value().ConductivityError()) + Gamma(4096) * Norm(k));
}
}
TEST(ThermalShell, RejectsUnrepresentablePositivePropertiesWithoutClamping) {
const auto underflow =
fesa::ThermalShell::Create({"patch", 19, "0019"}, {{0, 1, 2, 3}}, kSquare,
1, std::numeric_limits<double>::denorm_min(),
std::numeric_limits<double>::denorm_min(), 1);
EXPECT_FALSE(underflow.HasValue());
const auto overflow =
fesa::ThermalShell::Create({"patch", 19, "0019"}, {{0, 1, 2, 3}}, kSquare,
1, std::numeric_limits<double>::max(), 2, 1);
EXPECT_FALSE(overflow.HasValue());
}
@@ -0,0 +1,212 @@
#include <gtest/gtest.h>
#include <array>
#include <cmath>
#include <limits>
#include <string>
#include "fesa/elements/thermal_shell.h"
#include "fesa/model/domain.h"
namespace {
using fesa::Vector3;
using Patch = std::array<Vector3, 4>;
const Patch kSquare{{{0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}}};
fesa::Result<fesa::ThermalShell> Kernel(const Patch& patch) {
return fesa::ThermalShell::Create({"part", 27, "0027"}, {{0, 1, 2, 3}}, patch,
1., 1., 1., 1., {"mesh.inp", 17});
}
fesa::ModelDefinition Mesh(
const std::vector<Vector3>& nodes,
const std::vector<std::array<fesa::EntityIndex, 4>>& elements) {
fesa::ModelDefinition model{};
for (std::size_t i = 0; i < nodes.size(); ++i) {
model.nodes.push_back(
{{"part", static_cast<std::int64_t>(i + 1), std::to_string(i + 1)},
nodes[i].Components(),
{"mesh.inp", i + 1}});
}
model.thermal_materials.push_back({{"part", 1, "1"}, "heat", 1, 1, 1, {}});
model.thermal_sections.push_back({{"part", 1, "1"}, "section", 1, 0, {}});
for (std::size_t i = 0; i < elements.size(); ++i) {
model.thermal_elements.push_back(
{{"part", static_cast<std::int64_t>(i + 1), std::to_string(i + 1)},
elements[i],
0,
{"mesh.inp", i + 20}});
}
model.thermal_step = fesa::ThermalStepDefinition{"heat", .1, 1., 10};
return model;
}
bool Accepted(fesa::ModelDefinition model) {
return fesa::Domain::Create(std::move(model)).HasValue();
}
} // namespace
TEST(ThermalShellGeometry, CertifiesAffineDistortedSaddleAndSlenderPatches) {
EXPECT_TRUE(Kernel(kSquare).HasValue());
EXPECT_TRUE(
Kernel({{{0, 0, 0}, {2, 0, 0}, {3, 1, 0}, {1, 1, 0}}}).HasValue());
EXPECT_TRUE(
Kernel({{{0, 0, 0}, {2, 0, 0}, {1.5, 1, 0}, {0, 1, 0}}}).HasValue());
EXPECT_TRUE(Kernel({{{0, 0, 0},
{1, 0, 0},
{1, std::ldexp(1., -40), 0},
{0, std::ldexp(1., -40), 0}}})
.HasValue());
for (double a : {.1, .5, 2.}) {
EXPECT_TRUE(
Kernel({{{-1, -1, a}, {1, -1, -a}, {1, 1, a}, {-1, 1, -a}}}).HasValue())
<< a;
}
}
TEST(ThermalShellGeometry, PowerOfTwoScalingTranslationAndRotation) {
for (int exponent : {-200, 0, 200}) {
Patch patch = kSquare;
for (auto& point : patch) point = std::ldexp(1., exponent) * point;
EXPECT_TRUE(Kernel(patch).HasValue()) << exponent;
}
Patch translated = kSquare;
Patch rotated = kSquare;
for (std::size_t i = 0; i < 4; ++i) {
translated[i] = translated[i] + Vector3{1048576., -1048576., 1048576.};
rotated[i] = Vector3{.6 * kSquare[i].X() - .8 * kSquare[i].Y(),
.8 * kSquare[i].X() + .6 * kSquare[i].Y(), 0};
}
EXPECT_TRUE(Kernel(translated).HasValue());
EXPECT_TRUE(Kernel(rotated).HasValue());
}
TEST(ThermalShellGeometry,
RejectsWholePatchSingularityDespiteNonzeroGaussPoints) {
Patch patch{};
const std::array<double, 4> xi{{-1, 1, 1, -1}};
const std::array<double, 4> eta{{-1, -1, 1, 1}};
for (std::size_t i = 0; i < 4; ++i)
patch[i] = {xi[i], (xi[i] - .25) * eta[i], 0};
const auto result = Kernel(patch);
ASSERT_FALSE(result.HasValue());
EXPECT_EQ(result.GetStatus().Diagnostics()[0].entity_identity, "part:0027");
EXPECT_EQ(result.GetStatus().Diagnostics()[0].location.line, 17U);
for (double q : {-std::sqrt(.6), 0., std::sqrt(.6)})
EXPECT_GT(std::abs(q - .25), 0.);
}
TEST(ThermalShellGeometry, RejectsInvalidAndDoesNotRepairUncertainGeometry) {
EXPECT_FALSE(
Kernel({{{0, 0, 0}, {1, 1, 0}, {1, 0, 0}, {0, 1, 0}}}).HasValue());
EXPECT_FALSE(
Kernel({{{0, 0, 0}, {1, 0, 0}, {2, 0, 0}, {3, 0, 0}}}).HasValue());
Patch repeated = kSquare;
repeated[2] = repeated[1];
EXPECT_FALSE(Kernel(repeated).HasValue());
for (double bad : {std::numeric_limits<double>::infinity(),
std::numeric_limits<double>::quiet_NaN()}) {
Patch patch = kSquare;
patch[0] = {bad, 0, 0};
EXPECT_FALSE(Kernel(patch).HasValue());
}
const auto duplicate = fesa::ThermalShell::Create(
{"part", 1, "1"}, {{0, 1, 1, 3}}, kSquare, 1, 1, 1, 1);
EXPECT_FALSE(duplicate.HasValue());
const double e = std::ldexp(1., -52);
const auto uncertain =
Kernel({{{-2, -2 - e, 0}, {0, -e, 0}, {2, 2 + e, 0}, {0, e, 0}}});
if (!uncertain.HasValue())
EXPECT_EQ(uncertain.GetStatus().Diagnostics()[0].code,
"uncertain-thermal-shell-geometry");
}
TEST(ThermalShellGeometry, DomainEnforcesOppositeEdgesAndOneVertexLink) {
const std::vector<Vector3> nodes{{0, 0, 0}, {1, 0, 0}, {1, 1, 0},
{0, 1, 0}, {2, 0, 0}, {2, 1, 0}};
EXPECT_TRUE(Accepted(Mesh(nodes, {{{0, 1, 2, 3}}, {{1, 4, 5, 2}}})));
EXPECT_FALSE(Accepted(Mesh(nodes, {{{0, 1, 2, 3}}, {{2, 5, 4, 1}}})));
EXPECT_FALSE(Accepted(Mesh(nodes, {{{0, 1, 2, 3}}, {{0, 1, 2, 3}}})));
EXPECT_FALSE(Accepted(Mesh({{0, 0, 0},
{1, 0, 0},
{1, 1, 0},
{0, 1, 0},
{-1, -1, 0},
{0, -1, 0},
{-1, 0, 0}},
{{{0, 1, 2, 3}}, {{0, 6, 4, 5}}})));
EXPECT_FALSE(
Accepted(Mesh({{0, 0, 0},
{1, 0, 0},
{1, 1, 0},
{0, 1, 0},
{2, 0, 0},
{2, 1, 0},
{1, 0, 1},
{1, 1, 1}},
{{{0, 1, 2, 3}}, {{1, 4, 5, 2}}, {{1, 6, 7, 2}}})));
}
TEST(ThermalShellGeometry, DomainAllowsFoldAndDisconnectedCoordinateContact) {
auto folded =
Mesh({{0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}, {1, 0, 1}, {1, 1, 1}},
{{{0, 1, 2, 3}}, {{1, 4, 5, 2}}});
folded.thermal_materials.push_back({{"part", 2, "2"}, "heat2", 10, 1, 1, {}});
folded.thermal_sections.push_back({{"part", 2, "2"}, "section2", .5, 1, {}});
folded.thermal_elements[1].section_index = 1;
EXPECT_TRUE(Accepted(std::move(folded)));
const std::vector<Vector3> nodes{{0, 0, 0}, {2, 0, 0}, {2, 1, 0},
{0, 1, 0}, {0, 0, 0}, {1, 0, 0},
{1, -1, 0}, {0, -1, 0}};
auto disconnected = Mesh(nodes, {{{0, 1, 2, 3}}, {{4, 5, 6, 7}}});
EXPECT_TRUE(Accepted(disconnected));
for (std::size_t i = 4; i < 8; ++i)
disconnected.nodes[i].source_id.instance_name = "other";
disconnected.thermal_elements[1].source_id.instance_name = "other";
EXPECT_TRUE(Accepted(disconnected));
}
TEST(ThermalShellGeometry,
DomainRejectsSourceSharingPartialEdgeWithoutGlobalScan) {
// The patches share the full 3->0 / 0->3 edge: connected vertex links remain
// paths, while the additional 0->4 edge lies inside coarse 0->1.
const std::vector<Vector3> nodes{{0, 0, 0}, {2, 0, 0}, {2, 1, 0},
{0, 1, 0}, {1, 0, 0}, {1, 1, 1}};
const auto model = Mesh(nodes, {{{0, 1, 2, 3}}, {{0, 3, 5, 4}}});
const auto result = fesa::Domain::Create(model);
ASSERT_FALSE(result.HasValue());
EXPECT_EQ(result.GetStatus().Diagnostics()[0].code,
"uncertain-thermal-shell-connection");
auto invalid =
Mesh({{0, 0, 0}, {1, 1, 0}, {1, 0, 0}, {0, 1, 0}}, {{{0, 1, 2, 3}}});
EXPECT_FALSE(Accepted(invalid));
}
TEST(ThermalShellGeometry, SearchesSeparatingDirectionsBeyondCenterAndCorners) {
// Exact raw certificate s=(0,-3,6) has min(s.w)=9; center has zero margin.
EXPECT_TRUE(
Kernel({{{3, -9, -3}, {1, 3, -3}, {-1, 3, 3}, {-3, 3, 3}}}).HasValue());
// Exact s=(1.5,2.5,1) gives min(s.w)=3.5, whereas center/corner candidates
// cannot separate the normal image. Edge/interior minimization is needed.
EXPECT_TRUE(
Kernel({{{-1, 4, -4}, {-1, -2, 2}, {3, 2, 4}, {-1, -4, -2}}}).HasValue());
}
TEST(ThermalShellGeometry,
RejectsAliasedSourceIdentityAndAcceptsClosedVertexLink) {
auto aliases =
Mesh({{0, 0, 0}, {1, 0, 0}, {1, 1, 0}, {0, 1, 0}}, {{{0, 1, 2, 3}}});
aliases.nodes[2].source_id = aliases.nodes[1].source_id;
EXPECT_FALSE(Accepted(aliases));
EXPECT_TRUE(Accepted(
Mesh({{-1, -1, 0},
{0, -1, 0},
{1, -1, 0},
{-1, 0, 0},
{0, 0, 0},
{1, 0, 0},
{-1, 1, 0},
{0, 1, 0},
{1, 1, 0}},
{{{0, 1, 4, 3}}, {{1, 2, 5, 4}}, {{3, 4, 7, 6}}, {{4, 5, 8, 7}}})));
}