Class NumericalDynamics

Inheritance Relationships

Base Type

Derived Types

Class Documentation

class NumericalDynamics : public lupnt::Dynamics

Subclassed by lupnt::CartesianTwoBodyDynamics, lupnt::J2KeplerianDynamics, lupnt::JToCartTwoBodyDynamics, lupnt::JointOrbitClockDynamics, lupnt::MoonMeanDynamics, lupnt::NBodyDynamics

Public Functions

NumericalDynamics()
NumericalDynamics(Config &dynamics_config)
void SetTimeStep(Real dt)
Real GetTimeStep() const
void SetODE(ODE odefunc)
void SetIntegrator(IntegratorType integ)
void SetIntegratorParams(IntegratorParams params)
virtual VecX ComputeRates(Real t, const State &x) const
inline Integrator *GetIntegrator()
virtual State Propagate(const State &x0, Real t0, Real tf, const State *u = nullptr) override

Propagate the state from t0 to tf without computing a state transition matrix.

This is the core propagation entry point implemented by every concrete dynamics class (e.g. NumericalDynamics::Propagate, AnalyticalDynamics::Propagate, ClockDynamics::Propagate). It is called once per integration/measurement step by simulation drivers in applications/ and by agents/ to advance an object’s true or estimated state.

Parameters:

  • x0 – Initial state at time t0 (layout/units defined by the subclass).

  • t0 – Initial epoch [s, TDB since J2000 for orbit/attitude dynamics].

  • tf – Final epoch [s, TDB since J2000 for orbit/attitude dynamics].

  • u – Optional control/forcing input (e.g. thrust, RTN reference state); nullptr if unused.

Returns:

Propagated state at time tf.

inline virtual StateType GetStateType() const override

Return the StateType tag of the state vector this dynamics model operates on (e.g. Cart6::TYPE, Attitude::TYPE, ClockState3::TYPE).

Used by state-converters and asset wiring code to verify that a dynamics object is paired with a compatible state representation.

State PropagateEx(const State &x0, Real t0, Real tf, TerminationInfo *info)
MatX PropagateEx(const State &x0, Real t0, const VecX &tf, TerminationInfo *info)
State PropagateExStm(const State &x0, Real t0, Real tf, MatXd *stm, TerminationInfo *info)
virtual State Propagate(const State &x0, Real t0, Real tf, const State *u, MatXd *stm)

Propagate the state and compute the state transition matrix (STM) d(xf)/d(x0) via automatic differentiation.

Default implementation: if stm == nullptr, forwards to the no-STM Propagate overload; otherwise wraps Propagate(x0, t0, tf, u) in an autodiff Jacobian (jacobian(...)) with respect to x0. Used by filters (filters/) that need the linearized state transition for covariance propagation (e.g. EKF/UKF time updates).

Parameters:

  • x0 – Initial state at time t0.

  • t0 – Initial epoch [s, TDB since J2000].

  • tf – Final epoch [s, TDB since J2000].

  • u – Optional control/forcing input; nullptr if unused.

  • stm – Output: state transition matrix d(xf)/d(x0); left unmodified if nullptr.

Returns:

Propagated state at time tf.

virtual MatX Propagate(const State &x0, const VecX &tfs, const State *u = nullptr)

Propagate the state to a sequence of output epochs.

Repeatedly calls Propagate(x0, t0, tf, u) between consecutive entries of tfs, accumulating each result as a row of the returned matrix. Used by applications/ and analysis scripts to generate a full trajectory time history in one call, with optional progress-bar output (see SetPrintProgress).

Parameters:

  • x0 – Initial state at tfs(0).

  • tfs – Vector of output epochs [s, TDB since J2000], including the initial epoch as tfs(0).

  • u – Optional control/forcing input applied at every step; nullptr if unused.

Returns:

Matrix whose i-th row is the propagated state at tfs(i).