## Class MullerSolver

• All Implemented Interfaces:
BaseUnivariateSolver<UnivariateFunction>, UnivariateSolver

public class MullerSolver
extends AbstractUnivariateSolver
This class implements the Muller's Method for root finding of real univariate functions. For reference, see Elementary Numerical Analysis, ISBN 0070124477, chapter 3.

Muller's method applies to both real and complex functions, but here we restrict ourselves to real functions. This class differs from MullerSolver in the way it avoids complex operations.

Muller's original method would have function evaluation at complex point. Since our f(x) is real, we have to find ways to avoid that. Bracketing condition is one way to go: by requiring bracketing in every iteration, the newly computed approximation is guaranteed to be real.

Normally Muller's method converges quadratically in the vicinity of a zero, however it may be very slow in regions far away from zeros. For example, f(x) = exp(x) - 1, min = -50, max = 100. In such case we use bisection as a safety backup if it performs very poorly.

The formulas here use divided differences directly.

Since:
1.2
MullerSolver2
• ### Constructor Summary

Constructors
Constructor Description
MullerSolver()
Construct a solver with default accuracy (1e-6).
MullerSolver​(double absoluteAccuracy)
Construct a solver.
MullerSolver​(double relativeAccuracy, double absoluteAccuracy)
Construct a solver.
• ### Method Summary

All Methods
Modifier and Type Method Description
protected double doSolve()
Method for implementing actual optimization algorithms in derived classes.
• ### Methods inherited from class org.apache.commons.math4.legacy.analysis.solvers.BaseAbstractUnivariateSolver

computeObjectiveValue, getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMax, getMaxEvaluations, getMin, getRelativeAccuracy, getStartValue, incrementEvaluationCount, isBracketing, isSequence, setup, solve, 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 org.apache.commons.math4.legacy.analysis.solvers.BaseUnivariateSolver

getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMaxEvaluations, getRelativeAccuracy, solve, solve, solve
• ### Constructor Detail

• #### MullerSolver

public MullerSolver()
Construct a solver with default accuracy (1e-6).
• #### MullerSolver

public MullerSolver​(double absoluteAccuracy)
Construct a solver.
Parameters:
absoluteAccuracy - Absolute accuracy.
• #### MullerSolver

public MullerSolver​(double relativeAccuracy,
double absoluteAccuracy)
Construct a solver.
Parameters:
relativeAccuracy - Relative accuracy.
absoluteAccuracy - Absolute accuracy.
• ### Method Detail

• #### doSolve

protected double doSolve()
throws TooManyEvaluationsException,
NumberIsTooLargeException,
NoBracketingException
Method for implementing actual optimization algorithms in derived classes.
Specified by:
doSolve in class BaseAbstractUnivariateSolver<UnivariateFunction>
Returns:
the root.
Throws:
TooManyEvaluationsException - if the maximal number of evaluations is exceeded.
NoBracketingException - if the initial search interval does not bracket a root and the solver requires it.
NumberIsTooLargeException