it.uniroma2.sag.kelp.kernel.sequence

Class SequenceKernel

java.lang.Object

it.uniroma2.sag.kelp.kernel.Kernel

it.uniroma2.sag.kelp.kernel.DirectKernel<SequenceRepresentation>

it.uniroma2.sag.kelp.kernel.sequence.SequenceKernel

public class SequenceKernel
extends DirectKernel<SequenceRepresentation>

Sequence Kernel implementation.
A Sequence Kernel is a convolution kernel between sequences. The algorithm corresponds to the recursive computation presented in [Bunescu&Mooney,2006].

More information at:
[Bunescu&Mooney,2006] Razvan Bunescu and Raymond Mooney. Subsequence kernels for relation extraction. In Y. Weiss, B. Scholkopf, and J. Platt, editors, Advances in Neural Information Processing Systems 18, pages 171-178. MIT Press, Cambridge, MA, 2006.

Author:

Danilo Croce

Field Summary

Fields inherited from class it.uniroma2.sag.kelp.kernel.DirectKernel

representation

Constructor Summary

Constructors

Constructor and Description
SequenceKernel()
SequenceKernel(String representationIdentifier, int maxSubseqLeng, float lambda)

Method Summary

Modifier and Type	Method and Description
float	getLambda()
int	getMaxSubseqLeng()
float	kernelComputation(SequenceRepresentation repA, SequenceRepresentation repB) Computes the kernel similarity between two specific representations
void	setLambda(float lambda)
void	setMaxSubseqLeng(int maxSubseqLeng)

Methods inherited from class it.uniroma2.sag.kelp.kernel.DirectKernel

getRepresentation, kernelComputation, setRepresentation

Methods inherited from class it.uniroma2.sag.kelp.kernel.Kernel

disableCache, getKernelCache, getKernelComputations, getNumberOfHits, getNumberOfMisses, getSquaredNormCache, innerProduct, load, reset, save, setKernelCache, setSquaredNormCache, squaredNorm, squaredNormOfTheDifference

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceKernel

public SequenceKernel()

SequenceKernel

public SequenceKernel(String representationIdentifier,
                      int maxSubseqLeng,
                      float lambda)

Parameters:

representationIdentifier - Identifier of the Tree representation on which the kernel works

maxSubseqLeng - Maximum length of common subsequences

lambda - Gap penalty

Method Detail

getLambda

public float getLambda()

Returns:

Gap penalty

getMaxSubseqLeng

public int getMaxSubseqLeng()

Returns:

Maximum length of common subsequences

kernelComputation

public float kernelComputation(SequenceRepresentation repA,
                               SequenceRepresentation repB)

Description copied from class: DirectKernel

Computes the kernel similarity between two specific representations

Specified by:

kernelComputation in class DirectKernel<SequenceRepresentation>

Parameters:

repA - the first representation in the kernel similarity

repB - the second representation in the kernel similarity

Returns:

the kernel similarity

setLambda

public void setLambda(float lambda)

Parameters:

lambda - Gap penalty

setMaxSubseqLeng

public void setMaxSubseqLeng(int maxSubseqLeng)

Parameters:

maxSubseqLeng - Maximum length of common subsequences