Package smile.nlp.collocation

Class NGram

java.lang.Object

smile.nlp.NGram

smile.nlp.collocation.NGram

All Implemented Interfaces:

Comparable<NGram>

public class NGram
extends NGram
implements Comparable<NGram>

An n-gram is a contiguous sequence of n words from a given sequence of text. An n-gram of size 1 is referred to as an unigram; size 2 is a bigram; size 3 is a trigram.

Field Summary

Fields

Modifier and Type	Field	Description
final int	count	The frequency of n-gram in the corpus.

Fields inherited from class smile.nlp.NGram

words

Constructor Summary

Constructors

Constructor	Description
NGram(String[] words, int count)	Constructor.

Method Summary

Modifier and Type	Method	Description
int	compareTo(NGram o)
static NGram[][]	of(Collection<String[]> sentences, int maxNGramSize, int minFrequency)	Extracts n-gram phrases by an Apiori-like algorithm.
String	toString()

Methods inherited from class smile.nlp.NGram

equals, hashCode

Methods inherited from class java.lang.Object

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

Field Details

count

public final int count

The frequency of n-gram in the corpus.

Constructor Details

NGram

public NGram(String[] words,
 int count)

Constructor.

Parameters:

words - the n-gram word sequence.

count - the frequency of n-gram in the corpus.

Method Details

toString

public String toString()

Overrides:

toString in class NGram

compareTo

public int compareTo(NGram o)

Specified by:

compareTo in interface Comparable<NGram>

of

public static NGram[][] of(Collection<String[]> sentences,
 int maxNGramSize,
 int minFrequency)

Extracts n-gram phrases by an Apiori-like algorithm. The algorithm was proposed in "A Study Using n-gram Features for Text Categorization" by Johannes Furnkranz.

The algorithm takes a collection of sentences and generates all n-grams of length at most MaxNGramSize that occur at least MinFrequency times in the sentences.

Parameters:

sentences - A collection of sentences (already split).

maxNGramSize - The maximum length of n-gram

minFrequency - The minimum frequency of n-gram in the sentences.

Returns:

An array of n-gram sets. The i-th entry is the set of i-grams.