VectorRootSolver< InputT, OutputT > Class Template Reference

A vector-valued root solver using Newton's method. More...

#include <VectorRootSolver.h>

Inheritance diagram for VectorRootSolver< InputT, OutputT >:

Collaboration diagram for VectorRootSolver< InputT, OutputT >:

Public Types
using	InitialGuessSetter = std::function< void(const InputT &)>
using	StopCondition = std::function< bool()>
using	ResultExtractor = std::function< OutputT()>

Public Member Functions
	VectorRootSolver (InitialGuessSetter initialGuessSetter, StopCondition stopCondition, ResultExtractor extractResult, const OutputT &target, double tolerance=1e-3, int maxIterations=30, double jacobianStep=0.01, double damping=1.0)
	Construct a new VectorRootSolver object.
bool	stepFrame () override
	Performs one iteration of the vector root-finding solver.
Public Member Functions inherited from ISolver
virtual	~ISolver ()=default
	Virtual destructor for proper cleanup of derived classes.

Detailed Description

template<typename InputT, typename OutputT>
class VectorRootSolver< InputT, OutputT >

A vector-valued root solver using Newton's method.

This class attempts to find the input vector current such that the output of a function (extracted via ResultExtractor) matches a given target vector. It works in n-dimensional space (TODO: currently specialized for 3D vectors), using finite-difference approximations for the Jacobian.

The solver is designed to work asynchronously with a simulation loop:

• It does not advance the simulation internally.
• External code calls stepFrame() repeatedly after the simulation has advanced.

Definition at line 21 of file VectorRootSolver.h.

Member Typedef Documentation

InitialGuessSetter

template<typename InputT , typename OutputT >

using VectorRootSolver< InputT, OutputT >::InitialGuessSetter = std::function<void(const InputT&)>

Definition at line 23 of file VectorRootSolver.h.

ResultExtractor

template<typename InputT , typename OutputT >

using VectorRootSolver< InputT, OutputT >::ResultExtractor = std::function<OutputT()>

Definition at line 25 of file VectorRootSolver.h.

StopCondition

template<typename InputT , typename OutputT >

using VectorRootSolver< InputT, OutputT >::StopCondition = std::function<bool()>

Definition at line 24 of file VectorRootSolver.h.

Constructor & Destructor Documentation

VectorRootSolver()

template<typename InputT , typename OutputT >

VectorRootSolver< InputT, OutputT >::VectorRootSolver	(	InitialGuessSetter	initialGuessSetter,
		StopCondition	stopCondition,
		ResultExtractor	extractResult,
		const OutputT &	target,
		double	tolerance = 1e-3,
		int	maxIterations = 30,
		double	jacobianStep = 0.01,
		double	damping = 1.0
	)

Construct a new VectorRootSolver object.

Parameters

initialGuessSetter	Function to apply a new guess for the unknown input
stopCondition	Function to check if the simulation has reached the evaluation point
extractResult	Function to extract the output vector at the current guess
target	The target output vector the solver tries to reach
tolerance	Convergence tolerance for the error ||F(x) - target||
maxIterations	Maximum number of Newton iterations before giving up
jacobianStep	Step size for finite-difference Jacobian approximation
damping	Damping factor (alpha) for Newton step

Definition at line 10 of file VectorRootSolver.cpp.

Member Function Documentation

stepFrame()

template<typename InputT , typename OutputT >

bool VectorRootSolver< InputT, OutputT >::stepFrame ( )

overridevirtual

Performs one iteration of the vector root-finding solver.

This function attempts to improve the current guess for the unknown input by performing one step of Newton's method in N dimensions. It uses the current output (from extract()) and the target value to compute the error vector, approximates the Jacobian, and computes the next guess for the input using:

x_{n+1} = x_n - J(x_n)^{-1} * F(x_n)

where x_n is the current guess and F(x_n) = extract() - target.

The guess is applied via the setGuess() function.

Note

The actual simulation should be run externally. This function only updates the solver state and the next guess based on the most recent output.

Returns

true if the error norm ||F(x_n)|| is less than the solver's tolerance, indicating convergence to a root; false otherwise.

Implements ISolver.

Definition at line 18 of file VectorRootSolver.cpp.

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

• src/physics/solver/VectorRootSolver.h
• src/physics/solver/VectorRootSolver.cpp