srfm::tensor::GeodesicSolverN Class Reference

RK4 integrator for geodesics on an NAssetManifold. More...

#include <geodesic_n.hpp>

Public Member Functions
	GeodesicSolverN (const NAssetManifold &manifold, const ChristoffelN &christoffel) noexcept
	Construct from manifold and Christoffel symbol provider.
std::optional< GeodesicState >	step (const GeodesicState &s, double dtau) const noexcept
	Advance the geodesic by one RK4 step of proper-time dtau.
std::optional< std::vector< GeodesicState > >	integrate (GeodesicState initial, double dtau, int n_steps) const noexcept
	Integrate the geodesic for n_steps steps of size dtau.
std::optional< double >	geodesic_deviation (const std::vector< GeodesicState > &traj) const noexcept
	Measure the maximum deviation of a trajectory from a straight line.
int	dim () const noexcept
	Return the manifold dimension.

Detailed Description

RK4 integrator for geodesics on an NAssetManifold.

Definition at line 57 of file geodesic_n.hpp.

Constructor & Destructor Documentation

GeodesicSolverN()

srfm::tensor::GeodesicSolverN::GeodesicSolverN ( const NAssetManifold &  manifold, const ChristoffelN &  christoffel  )

noexcept

Construct from manifold and Christoffel symbol provider.

Both objects must outlive this solver.

Parameters

manifold	The underlying NAssetManifold.
christoffel	Christoffel symbol computation object.

Definition at line 28 of file geodesic_n.cpp.

Member Function Documentation

dim()

int srfm::tensor::GeodesicSolverN::dim ( ) const

inlinenoexcept

Return the manifold dimension.

Returns

manifold_.dim().

Definition at line 164 of file geodesic_n.hpp.

geodesic_deviation()

std::optional< double > srfm::tensor::GeodesicSolverN::geodesic_deviation ( const std::vector< GeodesicState > &  traj ) const

noexcept

Measure the maximum deviation of a trajectory from a straight line.

Computes the straight line from traj.front() to traj.back() and returns the maximum Euclidean distance in the spatial (price) components from any intermediate point to the corresponding point on that line.

This provides a measure of how non-geodesic the trajectory is in flat space.

Parameters

traj	Trajectory of geodesic states.

Returns

Max deviation, or std::nullopt if fewer than 2 states.

Definition at line 134 of file geodesic_n.cpp.

integrate()

std::optional< std::vector< GeodesicState > > srfm::tensor::GeodesicSolverN::integrate ( GeodesicState  initial, double  dtau, int  n_steps  ) const

noexcept

Integrate the geodesic for n_steps steps of size dtau.

Returns a vector of n_steps states (not including the initial state).

Parameters

initial	Starting state.
dtau	Proper-time step size.
n_steps	Number of steps to take.

Returns

Vector of states, or std::nullopt if any step fails.

Definition at line 114 of file geodesic_n.cpp.

step()

std::optional< GeodesicState > srfm::tensor::GeodesicSolverN::step ( const GeodesicState &  s, double  dtau  ) const

noexcept

Advance the geodesic by one RK4 step of proper-time dtau.

Computes k1..k4 for both position and velocity, then combines: s_new = s + (dtau/6)(k1 + 2k2 + 2k3 + k4)

Parameters

s	Current state (position + velocity).
dtau	Proper-time step size (may be negative for backward integration).

Returns

Updated state, or std::nullopt if Christoffel evaluation fails.

Definition at line 81 of file geodesic_n.cpp.

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The documentation for this class was generated from the following files:

• include/srfm/tensor/geodesic_n.hpp
• src/tensor/geodesic_n.cpp