com.sun.labs.minion.classification
Class FeaturePostings.Featurator

java.lang.Object
  com.sun.labs.minion.classification.FeaturePostings.Featurator

All Implemented Interfaces:

PostingsIterator

Enclosing class:

FeaturePostings

public class FeaturePostings.Featurator
extends java.lang.Object
implements PostingsIterator

Field Summary

protected int	curr The current ID.
protected int	off The current offset.

Constructor Summary

FeaturePostings.Featurator(PostingsIteratorFeatures features)

Method Summary

int	compareTo(java.lang.Object o) Compares this postings iterator to another one.
Feature	decode(Feature f) Decodes the current feature from the info buffer and returns it.
boolean	findID(int id) Finds the given document in the entry we're iterating through, if it exists.
int	get(int[] ids) Reads a number of IDs into the provided array.
int	get(int[] ids, float[] weights) Reads a number of IDs and the associated weights into the provided arrays.
int	get(int[] ids, int[] freq) Reads a number of IDs and frequencies into the provided arrays.
PostingsIteratorFeatures	getFeatures() Gets the features that were used to create this iterator.
int	getFreq() Gets the frequency of the term in the current document.
int	getID() Gets the document sequence number that the iterator is currently pointing at.
int	getN() Gets the number of IDs that this iterator will produce.
float	getWeight() Gets the weight of the term in the current document, as generated by some weighting function.
boolean	next() Moves to the next feature in the postings list.
void	reset() Resets the iterator to the beginning of the entry.

Methods inherited from class java.lang.Object

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

Field Detail

curr

protected int curr

The current ID.

off

protected int off

The current offset.

Constructor Detail

FeaturePostings.Featurator

public FeaturePostings.Featurator(PostingsIteratorFeatures features)

Method Detail

getFeatures

public PostingsIteratorFeatures getFeatures()

Description copied from interface: PostingsIterator

Gets the features that were used to create this iterator.

Specified by:

getFeatures in interface PostingsIterator

Returns:

the features used to create the iterator, or null if no features were used.

getN

public int getN()

Gets the number of IDs that this iterator will produce.

Specified by:

getN in interface PostingsIterator

next

public boolean next()

Moves to the next feature in the postings list.

Specified by:

next in interface PostingsIterator

Returns:

true if there is a next value, false otherwise.

findID

public boolean findID(int id)

Finds the given document in the entry we're iterating through, if it exists. If the document occurs in this entry, the iterator is left in a state where the data for that document has been decoded. If the document does not occur in this entry, the iterator is left in a state where the data for the next-highest document sequence number in this entry has been decoded.

Specified by:

findID in interface PostingsIterator

Parameters:

id - The ID that we want to find.

Returns:

true if the ID occurs in this entry, false otherwise.

See Also:

reset()

reset

public void reset()

Resets the iterator to the beginning of the entry. Data will not be decoded until the next method is called.

Specified by:

reset in interface PostingsIterator

getID

public int getID()

Gets the document sequence number that the iterator is currently pointing at.

Specified by:

getID in interface PostingsIterator

Returns:

The document sequence number that the iterator is pointing at, or 0 if the iterator has not been advanced yet, or has been exhausted.

getWeight

public float getWeight()

Gets the weight of the term in the current document, as generated by some weighting function.

Specified by:

getWeight in interface PostingsIterator

getFreq

public int getFreq()

Gets the frequency of the term in the current document.

Specified by:

getFreq in interface PostingsIterator

get

public int get(int[] ids)

Description copied from interface: PostingsIterator

Reads a number of IDs into the provided array.

Specified by:

get in interface PostingsIterator

get

public int get(int[] ids,
               int[] freq)

Description copied from interface: PostingsIterator

Reads a number of IDs and frequencies into the provided arrays.

Specified by:

get in interface PostingsIterator

Parameters:

ids - an array into which IDs will be placed. If possible, the array will be filled.

freq - an array into which frequencies will be placed. If possible, the array will be filled.

Returns:

the number of ids and frequencies read into the array, which may be smaller than the size of the array.

get

public int get(int[] ids,
               float[] weights)

Description copied from interface: PostingsIterator

Reads a number of IDs and the associated weights into the provided arrays.

Specified by:

get in interface PostingsIterator

Parameters:

ids - an array into which IDs will be placed. If possible, the array will be filled.

weights - an array into which weights will be placed. If possible, the array will be filled.

Returns:

the number of ids and frequencies read into the array, which may be smaller than the size of the array.

compareTo

public int compareTo(java.lang.Object o)

Compares this postings iterator to another one. Typically this comparison should be based on the ID at the head of the iterator.

Specified by:

compareTo in interface PostingsIterator

decode

public Feature decode(Feature f)

Decodes the current feature from the info buffer and returns it.

Parameters:

f - the feature into which we'll decode

Returns:

the decoded feature.