org.apache.spark.mllib.feature

Class Word2Vec

Object

org.apache.spark.mllib.feature.Word2Vec

All Implemented Interfaces:

java.io.Serializable, Logging

public class Word2Vec
extends Object
implements scala.Serializable, Logging

Word2Vec creates vector representation of words in a text corpus. The algorithm first constructs a vocabulary from the corpus and then learns vector representation of words in the vocabulary. The vector representation can be used as features in natural language processing and machine learning algorithms.

We used skip-gram model in our implementation and hierarchical softmax method to train the model. The variable names in the implementation matches the original C implementation.

For original C implementation, see https://code.google.com/p/word2vec/ For research papers, see Efficient Estimation of Word Representations in Vector Space and Distributed Representations of Words and Phrases and their Compositionality.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Word2Vec()

Method Summary

Modifier and Type	Method and Description
<S extends Iterable<String>> Word2VecModel	fit(JavaRDD<S> dataset) Computes the vector representation of each word in vocabulary (Java version).
<S extends scala.collection.Iterable<String>> Word2VecModel	fit(RDD<S> dataset) Computes the vector representation of each word in vocabulary.
Word2Vec	setLearningRate(double learningRate) Sets initial learning rate (default: 0.025).
Word2Vec	setMaxSentenceLength(int maxSentenceLength) Sets the maximum length (in words) of each sentence in the input data.
Word2Vec	setMinCount(int minCount) Sets minCount, the minimum number of times a token must appear to be included in the word2vec model's vocabulary (default: 5).
Word2Vec	setNumIterations(int numIterations) Sets number of iterations (default: 1), which should be smaller than or equal to number of partitions.
Word2Vec	setNumPartitions(int numPartitions) Sets number of partitions (default: 1).
Word2Vec	setSeed(long seed) Sets random seed (default: a random long integer).
Word2Vec	setVectorSize(int vectorSize) Sets vector size (default: 100).
Word2Vec	setWindowSize(int window) Sets the window of words (default: 5)

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.internal.Logging

initializeLogging, initializeLogIfNecessary, initializeLogIfNecessary, isTraceEnabled, log_, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning

Constructor Detail

Word2Vec

public Word2Vec()

Method Detail

fit

public <S extends scala.collection.Iterable<String>> Word2VecModel fit(RDD<S> dataset)

Computes the vector representation of each word in vocabulary.

Parameters:

dataset - an RDD of sentences, each sentence is expressed as an iterable collection of words

Returns:

a Word2VecModel

fit

public <S extends Iterable<String>> Word2VecModel fit(JavaRDD<S> dataset)

Computes the vector representation of each word in vocabulary (Java version).

Parameters:

dataset - a JavaRDD of words

Returns:

a Word2VecModel

setLearningRate

public Word2Vec setLearningRate(double learningRate)

Sets initial learning rate (default: 0.025).

Parameters:

learningRate - (undocumented)

Returns:

(undocumented)

setMaxSentenceLength

public Word2Vec setMaxSentenceLength(int maxSentenceLength)

Sets the maximum length (in words) of each sentence in the input data. Any sentence longer than this threshold will be divided into chunks of up to maxSentenceLength size (default: 1000)

Parameters:

maxSentenceLength - (undocumented)

Returns:

(undocumented)

setMinCount

public Word2Vec setMinCount(int minCount)

Sets minCount, the minimum number of times a token must appear to be included in the word2vec model's vocabulary (default: 5).

Parameters:

minCount - (undocumented)

Returns:

(undocumented)

setNumIterations

public Word2Vec setNumIterations(int numIterations)

Sets number of iterations (default: 1), which should be smaller than or equal to number of partitions.

Parameters:

numIterations - (undocumented)

Returns:

(undocumented)

setNumPartitions

public Word2Vec setNumPartitions(int numPartitions)

Sets number of partitions (default: 1). Use a small number for accuracy.

Parameters:

numPartitions - (undocumented)

Returns:

(undocumented)

setSeed

public Word2Vec setSeed(long seed)

Sets random seed (default: a random long integer).

Parameters:

seed - (undocumented)

Returns:

(undocumented)

setVectorSize

public Word2Vec setVectorSize(int vectorSize)

Sets vector size (default: 100).

Parameters:

vectorSize - (undocumented)

Returns:

(undocumented)

setWindowSize

public Word2Vec setWindowSize(int window)

Sets the window of words (default: 5)

Parameters:

window - (undocumented)

Returns:

(undocumented)