net.sourceforge.cilib.functions.continuous.unconstrained
Class Spherical

java.lang.Object
  net.sourceforge.cilib.functions.Function
      net.sourceforge.cilib.functions.ContinuousFunction
          net.sourceforge.cilib.functions.continuous.unconstrained.Spherical

All Implemented Interfaces:

Serializable, Differentiable, Cloneable

public class Spherical
extends ContinuousFunction
implements Differentiable

Spherical function.

Reference: X. Yao, Y. Liu, G. Liu, Evolutionary Programming Made Faster, IEEE Transactions on Evolutionary Computation, 3(2):82--102, 1999

Characteristics:

• Unimodal
• Continuous
• Separable
• Regular
• Convex

f(x) = 0; x = (0,0,...,0) x e [-5.12, 5.12]

Author:

Edwin Peer

See Also:

Serialized Form

Constructor Summary

Spherical()
Create a new instance of Spherical.

Method Summary

double	evaluate(Vector x) Evaluate the function with the given Vector as input.
Spherical	getClone() Create a cloned copy of the current object and return it.
Vector	getGradient(Vector x) Obtain the gradient Vector for the provided input Vector.
Object	getMinimum() Get the minimum of the function.

Methods inherited from class net.sourceforge.cilib.functions.ContinuousFunction

evaluate, getMaximum

Methods inherited from class net.sourceforge.cilib.functions.Function

getBehavioralDomainRegistry, getDimension, getDomain, getDomainRegistry, setBehavioralDomain, setBehaviouralDomainRegistry, setDomain

Methods inherited from class java.lang.Object

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

Constructor Detail

Spherical

public Spherical()

Create a new instance of Spherical.

Method Detail

getClone

public Spherical getClone()

Create a cloned copy of the current object and return it. In general the created copy will be a deep copy of the provided instance. As a result this operation an be quite expensive if used incorrectly.

Specified by:

getClone in interface Cloneable

Specified by:

getClone in class ContinuousFunction

Returns:

An exact clone of the current object instance.

See Also:

Object.clone()

getMinimum

public Object getMinimum()

Get the minimum of the function. It is defined to be a value of 0.0.

Overrides:

getMinimum in class ContinuousFunction

Returns:

The function minimum value.

evaluate

public double evaluate(Vector x)

Evaluate the function with the given Vector as input.

Specified by:

evaluate in class ContinuousFunction

Parameters:

x - The input Vector.

Returns:

The value of the evaluation.

getGradient

public Vector getGradient(Vector x)

Obtain the gradient Vector for the provided input Vector. The gradient is, naturally, the derivative of the Function which implements this interface.

Specified by:

getGradient in interface Differentiable

Parameters:

x - The provided input Vector to calculate the derivative at.

Returns:

A Vector containing the gradient of the provided input.