org.nd4j.linalg.lossfunctions.impl

Class LossPoisson

java.lang.Object

org.nd4j.linalg.lossfunctions.impl.LossPoisson

All Implemented Interfaces:

Serializable, ILossFunction

public class LossPoisson
extends Object
implements ILossFunction

Created by susaneraly on 9/9/16.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LossPoisson()

Method Summary

Modifier and Type	Method and Description
INDArray	computeGradient(INDArray labels, INDArray preOutput, String activationFn, INDArray mask) Compute the gradient of the loss function with respect to the inputs: dL/dOutput
org.apache.commons.math3.util.Pair<Double,INDArray>	computeGradientAndScore(INDArray labels, INDArray preOutput, String activationFn, INDArray mask, boolean average) Compute both the score (loss function value) and gradient.
double	computeScore(INDArray labels, INDArray preOutput, String activationFn, INDArray mask, boolean average) Compute the score (loss function value) for the given inputs.
INDArray	computeScoreArray(INDArray labels, INDArray preOutput, String activationFn, INDArray mask) Compute the score (loss function value) for each example individually.
INDArray	scoreArray(INDArray labels, INDArray preOutput, String activationFn, INDArray mask)
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

LossPoisson

public LossPoisson()

Method Detail

scoreArray

public INDArray scoreArray(INDArray labels,
                           INDArray preOutput,
                           String activationFn,
                           INDArray mask)

computeScore

public double computeScore(INDArray labels,
                           INDArray preOutput,
                           String activationFn,
                           INDArray mask,
                           boolean average)

Description copied from interface: ILossFunction

Compute the score (loss function value) for the given inputs.

Specified by:

computeScore in interface ILossFunction

Parameters:

labels - Label/expected preOutput

preOutput - Output of the model (neural network)

activationFn - Activation function that should be applied to preOutput

mask - Mask array; may be null

average - Whether the score should be averaged (divided by number of rows in labels/preOutput) or not @return Loss function value

computeScoreArray

public INDArray computeScoreArray(INDArray labels,
                                  INDArray preOutput,
                                  String activationFn,
                                  INDArray mask)

Description copied from interface: ILossFunction

Compute the score (loss function value) for each example individually. For input [numExamples,nOut] returns scores as a column vector: [numExamples,1]

Specified by:

computeScoreArray in interface ILossFunction

Parameters:

labels - Labels/expected output

preOutput - Output of the model (neural network)

activationFn - Activation function that should be applied to preOutput

mask - @return Loss function value for each example; column vector

computeGradient

public INDArray computeGradient(INDArray labels,
                                INDArray preOutput,
                                String activationFn,
                                INDArray mask)

Description copied from interface: ILossFunction

Compute the gradient of the loss function with respect to the inputs: dL/dOutput

Specified by:

computeGradient in interface ILossFunction

Parameters:

labels - Label/expected output

preOutput - Output of the model (neural network), before the activation function is applied

activationFn - Activation function that should be applied to preOutput

mask - Mask array; may be null

Returns:

Gradient dL/dPreOut

computeGradientAndScore

public org.apache.commons.math3.util.Pair<Double,INDArray> computeGradientAndScore(INDArray labels,
                                                                                   INDArray preOutput,
                                                                                   String activationFn,
                                                                                   INDArray mask,
                                                                                   boolean average)

Description copied from interface: ILossFunction

Compute both the score (loss function value) and gradient. This is equivalent to calling ILossFunction.computeScore(INDArray, INDArray, String, INDArray, boolean) and ILossFunction.computeGradient(INDArray, INDArray, String, INDArray) individually

Specified by:

computeGradientAndScore in interface ILossFunction

Parameters:

labels - Label/expected output

preOutput - Output of the model (neural network)

activationFn - Activation function that should be applied to preOutput

mask - Mask array; may be null

average - Whether the score should be averaged (divided by number of rows in labels/output) or not

Returns:

The score (loss function value) and gradient

toString

public String toString()

Overrides:

toString in class Object