Source tree guide

A directory-by-directory guide to src/, for orientation when reading or extending the code. The physics behind each module is in Theory and modelling.

model_main/

  • model_main.cpp — main; argument handling, the --selftest path, and construction of agb::AGBStarModel.

agb_model/

The orchestrator (agb::AGBStarModel).

  • agb_model.cpp — construction, calcModel (outer loop), chemistryHydroIteration (inner loop), chemistryDustIteration, radiativeTransfer, temperatureIteration, and the convergence tests (checkFluxConvergence, checkEnergyBalance, checkConvergence).

  • anderson_step.cpp — Anderson mixing of the temperature profile.

  • movable_grid.cpp — the equidistribution regrid step.

config/

  • config.{h,cpp} — agb::ModelConfig: every parameter, its default, and the toml++ parsing. This is the authoritative list of configuration keys (Configuration (config.toml)).

spectral_grid/

agb::SpectralGrid.

  • spectral_grid.cpp — load the global wavenumber list, build the constant-resolution working grid.

  • convert.cpp — wavelength ↔ wavenumber conversions.

  • spectral_grid_interpolate.cpp — interpolation onto the grids.

atmosphere/

agb::Atmosphere — the shared structure and opacity store.

  • atmosphere.cpp — construction, equation of state, the grey (Lucy) starting model (buildGreyStart), and the movable-grid remap (remapToGrid).

  • atmosphere_read_write.cpp — read/write the structure file (format).

chemistry/

agb::FastChemChemistry — the FastChem wrapper (fastchem_chemistry.cpp); chem_species.h holds the species identifiers and the physical-constants species table.

transport_coefficients/

The gas opacities (agb::TransportCoefficients, agb::OpacitySpecies).

  • transport_coeff.cpp — assemble all gas species’ contributions.

  • opacity_species.cpp — sampled line cross sections, interpolation, Rayleigh/continuum hooks.

  • cross_section_file.cpp, sampled_data.cpp — read and store the tabulated cross sections (agb::SampledData).

  • h_m.cpp, h2_m.cpp — H⁻ and H₂⁻ continuum absorption.

  • species_rayleigh_cross_sections.cpp — Rayleigh scattering.

  • species_definition.h — per-species data.

radiative_transfer/

The VEF moment radiative transfer (agb::RadiativeTransfer, agb::RadiationField, agb::ImpactParam).

  • radiative_transfer.cpp — driver solveRadiativeTransfer, geometry setup, Eddington/sphericality factors, emission precompute.

  • impact_parameter.cpp — the tangent-ray (Feautrier) formal solution.

  • moment_system.cpp — the \(J_\nu\) moment system (Taylor/spline assembly), calcFlux, the conservative flux integral, and buildLinearisedMomentSystem for the corrector.

  • radiation_field.cpp — moment storage, angular/wavelength integration, the flux-mean extinction.

  • output.cpp — saveSpectrum.

temperature_correction/

agb::TemperatureCorrection.

  • temperature_correction.cpp — Unsöld–Lucy (calculate), the integrated quantities, correction smoothing, Λ-iteration helper.

  • temperature_correction_linearisation.cpp — the full-linearisation Newton corrector (RE constraints, Rybicki elimination, dense \(2D\times2D\) solve).

dust/

  • dust_species.{h,cpp} — abstract agb::DustSpecies base.

  • gail_sedlmayr_dust.cpp — the moment method with carbon depletion (calcDistribution), nucleation/growth rates, the Mie opacity.

  • gail_sedlmayr_thermo_functions.cpp — the nucleation thermochemistry (saturation, critical cluster, free energy, Zeldovich factor, …).

  • analytic_dust.{h,cpp} — a simple analytic dust prescription for testing.

hydrodynamics/

agb::Hydrodynamics and the optional agb::StructureSolver.

  • hydrodynamics.cpp — the Melia Φ shooting solver, critical-point search, mass-loss eigenvalue, alpha, density, output.

  • structure_solver.cpp — the Henyey global-Newton solver (residuals, scaling, grey bootstrap, eigenvalue solve).

  • henyey_solver.cpp — the CppAD Newton/Jacobian driver and self-tests.

additional/

Shared utilities: aux_functions (Planck function, integration, equidistributedGrid), physical_const.h (cgs constants and the species table), tri_diagonal_matrix.h (Thomas solver with non-allocating solveInto), interpolation.h, quadrature.h, movable_grid.h, solve_linear_system.h, exceptions.h.