org.apache.commons.math3.analysis.solvers

Class IllinoisSolver

java.lang.Object

org.apache.commons.math3.analysis.solvers.BaseAbstractUnivariateSolver<UnivariateFunction>

org.apache.commons.math3.analysis.solvers.AbstractUnivariateSolver

org.apache.commons.math3.analysis.solvers.BaseSecantSolver

org.apache.commons.math3.analysis.solvers.IllinoisSolver

All Implemented Interfaces:

BaseUnivariateSolver<UnivariateFunction>, BracketedUnivariateSolver<UnivariateFunction>, UnivariateSolver

public class IllinoisSolver
extends BaseSecantSolver

Implements the Illinois 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 Illinois method however, should converge much faster than the original Regula Falsi method. Furthermore, this implementation of the Illinois method should not suffer from the same implementation issues as the Regula Falsi method, which may fail to convergence in certain cases.

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

Implementation based on the following article: M. Dowell and P. Jarratt, A modified regula falsi method for computing the root of an equation, BIT Numerical Mathematics, volume 11, number 2, pages 168-174, Springer, 1971.

Since:

3.0

Constructor Summary

Constructors

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

Method Summary

Methods inherited from class org.apache.commons.math3.analysis.solvers.BaseSecantSolver

solve, solve, solve

Methods inherited from class org.apache.commons.math3.analysis.solvers.BaseAbstractUnivariateSolver

getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMax, getMaxEvaluations, getMin, getRelativeAccuracy, getStartValue, solve, solve

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.math3.analysis.solvers.BaseUnivariateSolver

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

Constructor Detail

IllinoisSolver

public IllinoisSolver()

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

IllinoisSolver

public IllinoisSolver(double absoluteAccuracy)

Construct a solver.

Parameters:

absoluteAccuracy - Absolute accuracy.

IllinoisSolver

public IllinoisSolver(double relativeAccuracy,
                      double absoluteAccuracy)

Construct a solver.

Parameters:

relativeAccuracy - Relative accuracy.

absoluteAccuracy - Absolute accuracy.

IllinoisSolver

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

Construct a solver.

Parameters:

relativeAccuracy - Relative accuracy.

absoluteAccuracy - Absolute accuracy.

functionValueAccuracy - Maximum function value error.