SecantSolver (Apache Commons Math (Legacy) 4.0-SNAPSHOT API)

java.lang.Object
- org.apache.commons.math4.legacy.analysis.solvers.BaseAbstractUnivariateSolver<UnivariateFunction>
- - org.apache.commons.math4.legacy.analysis.solvers.AbstractUnivariateSolver
  - - org.apache.commons.math4.legacy.analysis.solvers.SecantSolver

All Implemented Interfaces:

BaseUnivariateSolver<UnivariateFunction>, UnivariateSolver
```
public class SecantSolver
extends AbstractUnivariateSolver
```
Implements the Secant method for root-finding (approximating a zero of a univariate real function). The solution that is maintained is not bracketed, and as such convergence is not guaranteed.
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.

Note that since release 3.0 this class implements the actual Secant algorithm, and not a modified one. As such, the 3.0 version is not backwards compatible with previous versions. To use an algorithm similar to the pre-3.0 releases, use the Illinois algorithm or the Pegasus algorithm.

Field Summary

Fields
Modifier and Type Field Description

protected static double DEFAULT_ABSOLUTE_ACCURACY
Default absolute accuracy.

Constructor Summary

Constructors
Constructor	Description
`SecantSolver()`	Construct a solver with default accuracy (1e-6).
`SecantSolver(double absoluteAccuracy)`	Construct a solver.
`SecantSolver(double relativeAccuracy, double absoluteAccuracy)`	Construct a solver.

Method Summary

All Methods Instance Methods Concrete 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

- Field Detail
  - DEFAULT_ABSOLUTE_ACCURACY
```
protected static final double DEFAULT_ABSOLUTE_ACCURACY
```
    Default absolute accuracy.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SecantSolver
```
public SecantSolver()
```
    Construct a solver with default accuracy (1e-6).
  - SecantSolver
```
public SecantSolver(double absoluteAccuracy)
```
    Construct a solver.
    
    Parameters:
    
    absoluteAccuracy - absolute accuracy
  - SecantSolver
```
public SecantSolver(double relativeAccuracy,
                    double absoluteAccuracy)
```
    Construct a solver.
    
    Parameters:
    
    relativeAccuracy - relative accuracy
    
    absoluteAccuracy - absolute accuracy
- Method Detail
  - doSolve
```
protected final double doSolve()
                        throws TooManyEvaluationsException,
                               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.