org.apache.mahout.classifier.sgd
Class DefaultGradient

java.lang.Object
  extended by org.apache.mahout.classifier.sgd.DefaultGradient
All Implemented Interfaces:
Gradient

public class DefaultGradient
extends Object
implements Gradient

Implements the basic logistic training law.


Constructor Summary
DefaultGradient()
           
 
Method Summary
 Vector apply(String groupKey, int actual, Vector instance, AbstractVectorClassifier classifier)
          Provides a default gradient computation useful for logistic regression.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DefaultGradient

public DefaultGradient()
Method Detail

apply

public final Vector apply(String groupKey,
                          int actual,
                          Vector instance,
                          AbstractVectorClassifier classifier)
Provides a default gradient computation useful for logistic regression.

Specified by:
apply in interface Gradient
Parameters:
groupKey - A grouping key to allow per-something AUC loss to be used for training.
actual - The target variable value.
instance - The current feature vector to use for gradient computation
classifier - The classifier that can compute scores
Returns:
The gradient to be applied to beta


Copyright © 2008–2014 The Apache Software Foundation. All rights reserved.