serif::utils::laneemden serif::utils::laneemden::IntegrationOptions serif::utils::laneemden::PhysicalSample serif::utils::laneemden::PhysicalScales serif::utils::laneemden::Sample serif::utils::laneemden::Solution std::expected< PhysicalScales, std::string > std::expected< PhysicalScales, std::string > serif::utils::laneemden::scale_from_mass (const Solution &solution, dimensions::QuantityValue< dimensions::Mass > mass, dimensions::QuantityValue< dimensions::MassDensity > central_density, dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant) scale_from_mass serif::utils::laneemden::scale_from_mass const Solution & solution dimensions::QuantityValue< dimensions::Mass > mass dimensions::QuantityValue< dimensions::MassDensity > central_density dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant Fix a reference star by mass and central density; its implied K is an output, never a change to an EOS. std::expected< PhysicalScales, std::string > std::expected< PhysicalScales, std::string > serif::utils::laneemden::scale_from_enthalpy (const Solution &solution, dimensions::QuantityValue< dimensions::SpecificEnthalpy > central_enthalpy, dimensions::QuantityValue< dimensions::MassDensity > central_density, dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant) scale_from_enthalpy serif::utils::laneemden::scale_from_enthalpy const Solution & solution dimensions::QuantityValue< dimensions::SpecificEnthalpy > central_enthalpy dimensions::QuantityValue< dimensions::MassDensity > central_density dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant Fix a physical star by central enthalpy and density, including the incompressible n = 0 limit. std::expected< PhysicalScales, std::string > std::expected< PhysicalScales, std::string > serif::utils::laneemden::scale_from_polytropic_constant (const Solution &solution, double polytropic_constant, dimensions::QuantityValue< dimensions::MassDensity > central_density, dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant) scale_from_polytropic_constant serif::utils::laneemden::scale_from_polytropic_constant const Solution & solution double polytropic_constant dimensions::QuantityValue< dimensions::MassDensity > central_density dimensions::QuantityValue< dimensions::GravitationalConstant > gravitational_constant Fix a polytropic EOS through its K and central density; n must be strictly positive. std::expected< PhysicalSample, std::string > std::expected< PhysicalSample, std::string > serif::utils::laneemden::evaluate_physical (const Solution &solution, const PhysicalScales &scales, dimensions::QuantityValue< dimensions::Length > radius) evaluate_physical serif::utils::laneemden::evaluate_physical const Solution & solution const PhysicalScales & scales dimensions::QuantityValue< dimensions::Length > radius Evaluate physical fields, continuing into vacuum beyond the stellar surface. The potential vanishes at infinity. Density, pressure, and enthalpy are zero at and beyond the surface, including the exterior side of the incompressible density jump. std::expected< Solution, std::string > std::expected< Solution, std::string > serif::utils::laneemden::solve (double n, IntegrationOptions options={}) solve serif::utils::laneemden::solve double n IntegrationOptions options {} Integrate theta'' + 2 theta'/xi + theta^n = 0 from the regular center. The central series follows Boudreaux's original power-series recurrence. Both dependent variables now advance through the same four Runge–Kutta stages. A missing surface is a valid finite-interval result, including the n >= 5 solutions. Exhausting the step budget or producing an unrepresentable numerical state returns a failure instead. std::expected< Sample, std::string > std::expected< Sample, std::string > serif::utils::laneemden::evaluate (const Solution &solution, double xi) evaluate serif::utils::laneemden::evaluate const Solution & solution double xi Evaluate a solved dimensionless profile with cubic Hermite interpolation, without extrapolation.