java.lang.Object
- cc.mallet.types.FeatureSequence

All Implemented Interfaces:

AlphabetCarrying, Sequence, java.io.Serializable

Direct Known Subclasses:

FeatureSequenceWithBigrams, LabelSequence
```
public class FeatureSequence
extends java.lang.Object
implements Sequence, java.io.Serializable, AlphabetCarrying
```
An implementation of Sequence that ensures that every Object in the sequence has the same class. Feature sequences are mutable, and will expand as new objects are added.

Author:

Andrew McCallum mccallum@cs.umass.edu

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor	Description
`FeatureSequence(Alphabet dict)`
`FeatureSequence(Alphabet dict, int capacity)`
`FeatureSequence(Alphabet dict, int[] features)`	Creates a FeatureSequence given all of the objects in the sequence.
`FeatureSequence(Alphabet dict, int[] features, int len)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`add(int featureIndex)`
`void`	`add(java.lang.Object key)`
`void`	`addFeatureWeightsTo(double[] weights)`
`void`	`addFeatureWeightsTo(double[] weights, double scale)`
`boolean`	`alphabetsMatch(AlphabetCarrying object)`
`java.lang.Object`	`get(int pos)`
`Alphabet`	`getAlphabet()`
`Alphabet[]`	`getAlphabets()`
`int[]`	`getFeatures()`
`int`	`getIndexAtPosition(int pos)`
`int`	`getLength()`
`java.lang.Object`	`getObjectAtPosition(int pos)`
`protected void`	`growIfNecessary()`
`void`	`prune(double[] counts, Alphabet newAlphabet, int cutoff)`	Remove features from the sequence that occur fewer than `cutoff` times in the corpus, as indicated by the provided counts.
`void`	`prune(Alphabet newAlphabet)`	Remove features from the sequence that occur fewer than `cutoff` times in the corpus, as indicated by the provided counts.
`int`	`size()`
`int[]`	`toFeatureIndexSequence()`
`int[]`	`toSortedFeatureIndexSequence()`
`java.lang.String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - FeatureSequence
```
public FeatureSequence(Alphabet dict,
                       int[] features)
```
    Creates a FeatureSequence given all of the objects in the sequence.
    
    Parameters:
    
    dict - A dictionary that maps objects in the sequence to numeric indices.
    
    features - An array where features[i] gives the index in dict of the ith element of the sequence.
  - FeatureSequence
```
public FeatureSequence(Alphabet dict,
                       int[] features,
                       int len)
```
  - FeatureSequence
```
public FeatureSequence(Alphabet dict,
                       int capacity)
```
  - FeatureSequence
```
public FeatureSequence(Alphabet dict)
```
- Method Detail
  - getFeatures
```
public int[] getFeatures()
```
  - getAlphabet
```
public Alphabet getAlphabet()
```
    Specified by:
    
    getAlphabet in interface AlphabetCarrying
  - getAlphabets
```
public Alphabet[] getAlphabets()
```
    Specified by:
    
    getAlphabets in interface AlphabetCarrying
  - alphabetsMatch
```
public boolean alphabetsMatch(AlphabetCarrying object)
```
  - getLength
```
public final int getLength()
```
  - size
```
public final int size()
```
    Specified by:
    
    size in interface Sequence
  - getIndexAtPosition
```
public final int getIndexAtPosition(int pos)
```
  - getObjectAtPosition
```
public java.lang.Object getObjectAtPosition(int pos)
```
  - get
```
public java.lang.Object get(int pos)
```
    Specified by:
    
    get in interface Sequence
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - growIfNecessary
```
protected void growIfNecessary()
```
  - add
```
public void add(int featureIndex)
```
  - add
```
public void add(java.lang.Object key)
```
  - addFeatureWeightsTo
```
public void addFeatureWeightsTo(double[] weights)
```
  - addFeatureWeightsTo
```
public void addFeatureWeightsTo(double[] weights,
                                double scale)
```
  - toFeatureIndexSequence
```
public int[] toFeatureIndexSequence()
```
  - toSortedFeatureIndexSequence
```
public int[] toSortedFeatureIndexSequence()
```
  - prune
```
public void prune(Alphabet newAlphabet)
```
    Remove features from the sequence that occur fewer than cutoff times in the corpus, as indicated by the provided counts. Also swap in the new, reduced alphabet. This method alters the instance in place; it is not appropriate if the original instance will be needed.
  - prune
```
public void prune(double[] counts,
                  Alphabet newAlphabet,
                  int cutoff)
```
    Remove features from the sequence that occur fewer than cutoff times in the corpus, as indicated by the provided counts. Also swap in the new, reduced alphabet. This method alters the instance in place; it is not appropriate if the original instance will be needed.

Class FeatureSequence

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FeatureSequence

FeatureSequence

FeatureSequence

FeatureSequence

Method Detail

getFeatures

getAlphabet

getAlphabets

alphabetsMatch

getLength

size

getIndexAtPosition

getObjectAtPosition

get

toString

growIfNecessary

add

add

addFeatureWeightsTo

addFeatureWeightsTo

toFeatureIndexSequence

toSortedFeatureIndexSequence

prune

prune