# directory

DiffEqStochastic and deterministic (ordinary) differential equations.

### Contents

- Reference

This directory contains implementations of discrete time integrators for deterministic and stochastic *ordinary* differential equations. (*Ordinary* as opposed to *partial* differential equations in `src/PDE`

). At this time, all of these ordinary differential equations are used exclusively by Walker.

`Configure<eq>.[Ch]`

contain functionality related to registration and querying user-configuration information on specific equation types.

All specific equation types "inherit" from the common "base", tk::DiffEq, so that user-configured instances of multiple specific equations (as a potentially coupled system) can be integrated in a generic fashion. This is done using concept-based runtime polymorphism.

The specific equation types are registered into a factory, walker::

## Files

- file Beta.h
- System of beta SDEs.
- file BetaCoeffPolicy.h
- Beta coefficients policies.
- file ConfigureBeta.C
- Register and compile configuration on the beta SDE.
- file ConfigureBeta.h
- Register and compile configuration on the beta SDE.
- file ConfigureDiagOrnsteinUhlenbeck.C
- Register and compile configuration on the diagonal Ornstein-Uhlenbeck SDE.
- file ConfigureDiagOrnsteinUhlenbeck.h
- Register and compile configuration on the diagonal Ornstein-Uhlenbeck SDE.
- file ConfigureDirichlet.C
- Register and compile configuration on the Dirichlet SDE.
- file ConfigureDirichlet.h
- Register and compile configuration on the Dirichlet SDE.
- file ConfigureDissipation.C
- Register and compile configuration on the dissipation SDE.
- file ConfigureDissipation.h
- Register and compile configuration on the dissipation SDE.
- file ConfigureGamma.C
- Register and compile configuration on the gamma SDE.
- file ConfigureGamma.h
- Register and compile configuration on the gamma SDE.
- file ConfigureGeneralizedDirichlet.C
- Register and compile configuration on the generlized Dirichlet SDE.
- file ConfigureGeneralizedDirichlet.h
- Register and compile configuration on the generalized Dirichlet SDE.
- file ConfigureMassFractionBeta.C
- Register and compile configuration on the mass fraction beta SDE.
- file ConfigureMassFractionBeta.h
- Register and compile configuration on the number fraction beta SDE.
- file ConfigureMixDirichlet.C
- Register and compile configuration on the MixDirichlet SDE.
- file ConfigureMixDirichlet.h
- Register and compile configuration on the MixDirichlet SDE.
- file ConfigureMixMassFractionBeta.C
- Register and compile configuration on the mix mass fraction beta SDE.
- file ConfigureMixMassFractionBeta.h
- Register and compile configuration on the mix mass fraction beta SDE.
- file ConfigureMixNumberFractionBeta.C
- Register and compile configuration on the mix number fraction beta SDE.
- file ConfigureMixNumberFractionBeta.h
- Register and compile configuration on the mix number fraction beta SDE.
- file ConfigureNumberFractionBeta.C
- Register and compile configuration on the number fraction beta SDE.
- file ConfigureNumberFractionBeta.h
- Register and compile configuration on the number fraction beta SDE.
- file ConfigureOrnsteinUhlenbeck.C
- Register and compile configuration on the Ornstein-Uhlenbeck SDE.
- file ConfigureOrnsteinUhlenbeck.h
- Register and compile configuration on the Ornstein-Uhlenbeck SDE.
- file ConfigurePosition.C
- Register and compile configuration on the position SDE.
- file ConfigurePosition.h
- Register and compile configuration on the position SDE.
- file ConfigureSkewNormal.C
- Register and compile configuration on the skew-normal SDE.
- file ConfigureSkewNormal.h
- Register and compile configuration on the skew-normal SDE.
- file ConfigureVelocity.C
- Register and compile configuration on the velocity SDE.
- file ConfigureVelocity.h
- Register and compile configuration on the velocity SDE.
- file ConfigureWrightFisher.C
- Register and compile configuration on the Wright-Fisher SDE.
- file ConfigureWrightFisher.h
- Register and compile configuration on the Wright-Fisher SDE.
- file CoupledEq.h
- Functionality for querying information on coupled equations.
- file DiagOrnsteinUhlenbeck.h
- System of diagonal Ornstein-Uhlenbeck SDEs.
- file DiagOrnsteinUhlenbeckCoeffPolicy.h
- Diagonal Ornstein-Uhlenbeck coefficients policies.
- file DiffEq.h
- Differential equation.
- file DiffEqFactory.h
- Differential equations factory.
- file DiffEqStack.C
- Stack of differential equations.
- file DiffEqStack.h
- Stack of differential equations.
- file Dirichlet.h
- Dirichlet SDE.
- file DirichletCoeffPolicy.h
- Dirichlet coefficients policies.
- file Dissipation.h
- A dissipation model for Lagrangian particles.
- file DissipationCoeffPolicy.h
- Particle dissipation equation coefficients policies.
- file Gamma.h
- System of gamma SDEs.
- file GammaCoeffPolicy.h
- Gamma coefficients policies.
- file GeneralizedDirichlet.h
- Lochner's generalized Dirichlet SDE.
- file GeneralizedDirichletCoeffPolicy.h
- Lochner's generalized Dirichlet coefficients policies.
- file HydroProductions.h
- Hydrodynamics (turbulent kinetic energy) production divided by the dissipation rate from DNS for the homogeneous Rayleigh-Taylor instability.
- file HydroTimeScales.h
- Inverse hydrodynamics time scales from DNS for the homogeneous Rayleigh-Taylor instability.
- file InitPolicy.h
- Initialization policies.
- file Langevin.C
- Functionality implementing Langevin models for the velocity.
- file Langevin.h
- Functionality implementing Langevin models for the velocity.
- file MassFractionBeta.h
- System of mass-fraction beta SDEs.
- file MassFractionBetaCoeffPolicy.h
- Mass-fraction beta SDE coefficients policies.
- file MixDirichlet.h
- Mixture Dirichlet SDE.
- file MixDirichletCoeffPolicy.h
- MixDirichlet coefficients policies.
- file MixMassFractionBeta.h
- System of mix mass-fraction beta SDEs.
- file MixMassFractionBetaCoeffPolicy.h
- Mix mass-fraction beta SDE coefficients policies.
- file MixNumberFractionBeta.h
- System of mix number-fraction beta SDEs.
- file MixNumberFractionBetaCoeffPolicy.h
- Mix number-fraction beta SDE coefficients policies.
- file NumberFractionBeta.h
- System of number-fraction beta SDEs.
- file NumberFractionBetaCoeffPolicy.h
- Number-fraction beta SDE coefficients policies.
- file OrnsteinUhlenbeck.h
- System of Ornstein-Uhlenbeck SDEs.
- file OrnsteinUhlenbeckCoeffPolicy.h
- Ornstein-Uhlenbeck coefficients policies.
- file Position.h
- A position model for Lagrangian particles.
- file PositionCoeffPolicy.h
- Particle position equation coefficients policies.
- file SkewNormal.h
- System of skew-normal SDEs.
- file SkewNormalCoeffPolicy.h
- Skew-normal coefficients policies.
- file Velocity.h
- A model for velocity in variable-density turbulence.
- file VelocityCoeffPolicy.h
- Velocity equation coefficients policies.
- file WrightFisher.h
- Wright-Fisher SDE.
- file WrightFisherCoeffPolicy.h
- Wright-Fisher coefficients policies.