org.apache.commons.math3.optim.nonlinear.scalar.noderiv

Class AbstractSimplex

java.lang.Object

org.apache.commons.math3.optim.nonlinear.scalar.noderiv.AbstractSimplex

All Implemented Interfaces:

OptimizationData

Direct Known Subclasses:

MultiDirectionalSimplex, NelderMeadSimplex

public abstract class AbstractSimplex
extends Object
implements OptimizationData

This class implements the simplex concept. It is intended to be used in conjunction with SimplexOptimizer.
The initial configuration of the simplex is set by the constructors AbstractSimplex(double[]) or AbstractSimplex(double[][]). The other constructor will set all steps to 1, thus building a default configuration from a unit hypercube.
Users must call the build method in order to create the data structure that will be acted on by the other methods of this class.

Since:

3.0

See Also:

SimplexOptimizer

Method Summary

Modifier and Type	Method and Description
void	build(double[] startPoint) Build an initial simplex.
void	evaluate(MultivariateFunction evaluationFunction, Comparator<PointValuePair> comparator) Evaluate all the non-evaluated points of the simplex.
int	getDimension() Get simplex dimension.
PointValuePair	getPoint(int index) Get the simplex point stored at the requested index.
PointValuePair[]	getPoints() Get the points of the simplex.
int	getSize() Get simplex size.
abstract void	iterate(MultivariateFunction evaluationFunction, Comparator<PointValuePair> comparator) Compute the next simplex of the algorithm.

Methods inherited from class java.lang.Object

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

Method Detail

getDimension

public int getDimension()

Get simplex dimension.

Returns:

the dimension of the simplex.

getSize

public int getSize()

Get simplex size. After calling the build method, this method will will be equivalent to getDimension() + 1.

Returns:

the size of the simplex.

iterate

public abstract void iterate(MultivariateFunction evaluationFunction,
                             Comparator<PointValuePair> comparator)

Compute the next simplex of the algorithm.

Parameters:

evaluationFunction - Evaluation function.

comparator - Comparator to use to sort simplex vertices from best to worst.

Throws:

TooManyEvaluationsException - if the algorithm fails to converge.

build

public void build(double[] startPoint)

Build an initial simplex.

Parameters:

startPoint - First point of the simplex.

Throws:

DimensionMismatchException - if the start point does not match simplex dimension.

evaluate

public void evaluate(MultivariateFunction evaluationFunction,
                     Comparator<PointValuePair> comparator)

Evaluate all the non-evaluated points of the simplex.

Parameters:

evaluationFunction - Evaluation function.

comparator - Comparator to use to sort simplex vertices from best to worst.

Throws:

TooManyEvaluationsException - if the maximal number of evaluations is exceeded.

getPoints

public PointValuePair[] getPoints()

Get the points of the simplex.

Returns:

all the simplex points.

getPoint

public PointValuePair getPoint(int index)

Get the simplex point stored at the requested index.

Parameters:

index - Location.

Returns:

the point at location index.