org.apache.mahout.classifier.sgd
Class L2
java.lang.Object
org.apache.mahout.classifier.sgd.L2
- All Implemented Interfaces:
- org.apache.hadoop.io.Writable, PriorFunction
public class L2
- extends Object
- implements PriorFunction
Implements the Gaussian prior. This prior has a tendency to decrease large coefficients toward zero, but
doesn't tend to set them to exactly zero.
Constructor Summary |
L2()
|
L2(double scale)
|
Method Summary |
double |
age(double oldValue,
double generations,
double learningRate)
Applies the regularization to a coefficient. |
double |
logP(double betaIJ)
Returns the log of the probability of a particular coefficient value according to the prior. |
void |
readFields(DataInput in)
|
void |
write(DataOutput out)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
L2
public L2(double scale)
L2
public L2()
age
public double age(double oldValue,
double generations,
double learningRate)
- Description copied from interface:
PriorFunction
- Applies the regularization to a coefficient.
- Specified by:
age
in interface PriorFunction
- Parameters:
oldValue
- The previous value.generations
- The number of generations.learningRate
- The learning rate with lambda baked in.
- Returns:
- The new coefficient value after regularization.
logP
public double logP(double betaIJ)
- Description copied from interface:
PriorFunction
- Returns the log of the probability of a particular coefficient value according to the prior.
- Specified by:
logP
in interface PriorFunction
- Parameters:
betaIJ
- The coefficient.
- Returns:
- The log probability.
write
public void write(DataOutput out)
throws IOException
- Specified by:
write
in interface org.apache.hadoop.io.Writable
- Throws:
IOException
readFields
public void readFields(DataInput in)
throws IOException
- Specified by:
readFields
in interface org.apache.hadoop.io.Writable
- Throws:
IOException
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