Class SecantSolver

  extended by org.apache.commons.math3.analysis.solvers.BaseAbstractUnivariateSolver<UnivariateFunction>
      extended by org.apache.commons.math3.analysis.solvers.AbstractUnivariateSolver
          extended by org.apache.commons.math3.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.

$Id: 1379560 2012-08-31 19:40:30Z erans $

Field Summary
protected static double DEFAULT_ABSOLUTE_ACCURACY
          Default absolute accuracy.
Constructor Summary
          Construct a solver with default accuracy (1e-6).
SecantSolver(double absoluteAccuracy)
          Construct a solver.
SecantSolver(double relativeAccuracy, double absoluteAccuracy)
          Construct a solver.
Method Summary
protected  double doSolve()
          Method for implementing actual optimization algorithms in derived classes.
Methods inherited from class org.apache.commons.math3.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.math3.analysis.solvers.BaseUnivariateSolver
getAbsoluteAccuracy, getEvaluations, getFunctionValueAccuracy, getMaxEvaluations, getRelativeAccuracy, solve, solve, solve

Field Detail


protected static final double DEFAULT_ABSOLUTE_ACCURACY
Default absolute accuracy.

See Also:
Constant Field Values
Constructor Detail


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


public SecantSolver(double absoluteAccuracy)
Construct a solver.

absoluteAccuracy - absolute accuracy


public SecantSolver(double relativeAccuracy,
                    double absoluteAccuracy)
Construct a solver.

relativeAccuracy - relative accuracy
absoluteAccuracy - absolute accuracy
Method Detail


protected final double doSolve()
                        throws TooManyEvaluationsException,
Method for implementing actual optimization algorithms in derived classes.

Specified by:
doSolve in class BaseAbstractUnivariateSolver<UnivariateFunction>
the root.
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.

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