fr.cnes.sirius.patrius.math.analysis.solver

Class PegasusSolver

java.lang.Object

fr.cnes.sirius.patrius.math.analysis.solver.BaseAbstractUnivariateSolver<UnivariateFunction>

fr.cnes.sirius.patrius.math.analysis.solver.AbstractUnivariateSolver

fr.cnes.sirius.patrius.math.analysis.solver.BaseSecantSolver

fr.cnes.sirius.patrius.math.analysis.solver.PegasusSolver

All Implemented Interfaces:

BaseUnivariateSolver<UnivariateFunction>, BracketedUnivariateSolver<UnivariateFunction>, UnivariateSolver, Serializable

public class PegasusSolver
extends BaseSecantSolver

Implements the Pegasus method for root-finding (approximating a zero of a univariate real function). It is a modified Regula Falsi method.

Like the Regula Falsi method, convergence is guaranteed by maintaining a bracketed solution. The Pegasus method however, should converge much faster than the original Regula Falsi method. Furthermore, this implementation of the Pegasus method should not suffer from the same implementation issues as the Regula Falsi method, which may fail to convergence in certain cases. Also, the Pegasus method should converge faster than the Illinois method, another Regula Falsi-based method.

The Pegasus method assumes that the function is continuous, but not necessarily smooth.

Implementation based on the following article: M. Dowell and P. Jarratt, The "Pegasus" method for computing the root of an equation, BIT Numerical Mathematics, volume 12, number 4, pages 503-508, Springer, 1972.

Since:

3.0

Version:

$Id: PegasusSolver.java 18108 2017-10-04 06:45:27Z bignon $

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class fr.cnes.sirius.patrius.math.analysis.solver.BaseSecantSolver

BaseSecantSolver.Method

Field Summary

Fields inherited from class fr.cnes.sirius.patrius.math.analysis.solver.BaseSecantSolver

DEFAULT_ABSOLUTE_ACCURACY

Constructor Summary

Constructors

Constructor and Description
PegasusSolver() Construct a solver with default accuracy (1e-6).
PegasusSolver(double absoluteAccuracy) Construct a solver.
PegasusSolver(double relativeAccuracy, double absoluteAccuracy) Construct a solver.
PegasusSolver(double relativeAccuracy, double absoluteAccuracy, double functionValueAccuracy) Construct a solver.

Method Summary

Methods inherited from class fr.cnes.sirius.patrius.math.analysis.solver.BaseSecantSolver

doSolve, solve, solve, solve

Methods inherited from class fr.cnes.sirius.patrius.math.analysis.solver.BaseAbstractUnivariateSolver

computeObjectiveValue, getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMax, getMaxEvaluations, getMin, getRelativeAccuracy, getStartValue, incrementEvaluationCount, isBracketing, isSequence, setup, solve, solve, verifyBracketing, verifyInterval, verifySequence

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface fr.cnes.sirius.patrius.math.analysis.solver.BaseUnivariateSolver

getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMaxEvaluations, getRelativeAccuracy, solve, solve

Constructor Detail

PegasusSolver

public PegasusSolver()

Construct a solver with default accuracy (1e-6).

PegasusSolver

public PegasusSolver(double absoluteAccuracy)

Construct a solver.

Parameters:

absoluteAccuracy - Absolute accuracy.

PegasusSolver

public PegasusSolver(double relativeAccuracy,
                     double absoluteAccuracy)

Construct a solver.

Parameters:

relativeAccuracy - Relative accuracy.

absoluteAccuracy - Absolute accuracy.

PegasusSolver

public PegasusSolver(double relativeAccuracy,
                     double absoluteAccuracy,
                     double functionValueAccuracy)

Construct a solver.

Parameters:

relativeAccuracy - Relative accuracy.

absoluteAccuracy - Absolute accuracy.

functionValueAccuracy - Maximum function value error.