org.encog.engine.network.activation
Class ActivationBiPolar

java.lang.Object
  org.encog.engine.network.activation.ActivationBiPolar

All Implemented Interfaces:

Serializable, Cloneable, ActivationFunction

public class ActivationBiPolar
extends Object
implements ActivationFunction

BiPolar activation function. This will scale the neural data into the bipolar range. Greater than zero becomes 1, less than or equal to zero becomes -1.

Author:

jheaton

See Also:

Serialized Form

Constructor Summary

ActivationBiPolar()
Construct the bipolar activation function.

Method Summary

void	activationFunction(double[] x, int start, int size) Implements the activation function.
ActivationFunction	clone()
double	derivativeFunction(double b, double a) Implements the activation function derivative.
String[]	getParamNames()
double[]	getParams()
boolean	hasDerivative()
void	setParam(int index, double value) Set one of the params for this activation function.

Methods inherited from class java.lang.Object

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

Constructor Detail

ActivationBiPolar

public ActivationBiPolar()

Construct the bipolar activation function.

Method Detail

activationFunction

public final void activationFunction(double[] x,
                                     int start,
                                     int size)

Implements the activation function. The array is modified according to the activation function being used. See the class description for more specific information on this type of activation function.

Specified by:

activationFunction in interface ActivationFunction

Parameters:

x - The input array to the activation function.

start - The starting index.

size - The number of values to calculate.

clone

public final ActivationFunction clone()

Specified by:

clone in interface ActivationFunction

Overrides:

clone in class Object

Returns:

The object cloned.

derivativeFunction

public final double derivativeFunction(double b,
                                       double a)

Implements the activation function derivative. The array is modified according derivative of the activation function being used. See the class description for more specific information on this type of activation function. Propagation training requires the derivative. Some activation functions do not support a derivative and will throw an error.

Specified by:

derivativeFunction in interface ActivationFunction

Parameters:

d - The input array to the activation function.

Returns:

The derivative.

getParamNames

public final String[] getParamNames()

Specified by:

getParamNames in interface ActivationFunction

Returns:

The names of the parameters.

getParams

public final double[] getParams()

Specified by:

getParams in interface ActivationFunction

Returns:

The params for this activation function.

hasDerivative

public final boolean hasDerivative()

Specified by:

hasDerivative in interface ActivationFunction

Returns:

Return true, bipolar has a 1 for derivative.

setParam

public final void setParam(int index,
                           double value)

Set one of the params for this activation function.

Specified by:

setParam in interface ActivationFunction

Parameters:

index - The index of the param to set.

value - The value to set.