org.apache.mahout.vectorizer.collocations.llr

Class Gram

java.lang.Object

org.apache.hadoop.io.BinaryComparable

org.apache.mahout.vectorizer.collocations.llr.Gram

All Implemented Interfaces:

Comparable<org.apache.hadoop.io.BinaryComparable>, org.apache.hadoop.io.Writable, org.apache.hadoop.io.WritableComparable<org.apache.hadoop.io.BinaryComparable>

public class Gram
extends org.apache.hadoop.io.BinaryComparable
implements org.apache.hadoop.io.WritableComparable<org.apache.hadoop.io.BinaryComparable>

Writable for holding data generated from the collocation discovery jobs. Depending on the job configuration gram may be one or more words. In some contexts this is used to hold a complete ngram, while in others it holds a part of an existing ngram (subgram). Tracks the frequency of the gram and its position in the ngram in which is was found.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Gram.Type

Constructor Summary

Constructors

Constructor and Description
Gram()
Gram(Gram other) Copy constructor
Gram(String ngram, Gram.Type type) Create an gram with a frequency of 1
Gram(String ngram, int frequency, Gram.Type type) Create a gram with the specified frequency.

Method Summary

Modifier and Type	Method and Description
static Gram.Type	decodeType(byte[] buf, int offset)
static void	encodeType(Gram.Type type, byte[] buf, int offset)
byte[]	getBytes()
int	getFrequency()
int	getLength()
String	getString()
Gram.Type	getType()
void	incrementFrequency(int i)
void	readFields(DataInput in)
void	setFrequency(int frequency)
String	toString()
void	write(DataOutput out)

Methods inherited from class org.apache.hadoop.io.BinaryComparable

compareTo, compareTo, equals, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Comparable

compareTo

Constructor Detail

Gram

public Gram()

Gram

public Gram(Gram other)

Copy constructor

Gram

public Gram(String ngram,
            Gram.Type type)

Create an gram with a frequency of 1

Parameters:

ngram - the gram string

type - whether the gram is at the head or tail of its text unit or it is a unigram

Gram

public Gram(String ngram,
            int frequency,
            Gram.Type type)

Create a gram with the specified frequency.

Parameters:

ngram - the gram string

frequency - the gram frequency

type - whether the gram is at the head of its text unit or tail or unigram

Method Detail

getBytes

public byte[] getBytes()

Specified by:

getBytes in class org.apache.hadoop.io.BinaryComparable

getLength

public int getLength()

Specified by:

getLength in class org.apache.hadoop.io.BinaryComparable

getType

public Gram.Type getType()

Returns:

the gram is at the head of its text unit or tail or unigram.

getString

public String getString()

Returns:

gram term string

getFrequency

public int getFrequency()

Returns:

gram frequency

setFrequency

public void setFrequency(int frequency)

Parameters:

frequency - gram's frequency

incrementFrequency

public void incrementFrequency(int i)

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

encodeType

public static void encodeType(Gram.Type type,
                              byte[] buf,
                              int offset)

decodeType

public static Gram.Type decodeType(byte[] buf,
                                   int offset)