Word2Vec

class pyspark.ml.feature.Word2Vec(vectorSize=100, minCount=5, numPartitions=1, stepSize=0.025, maxIter=1, seed=None, inputCol=None, outputCol=None, windowSize=5, maxSentenceLength=1000)[source]

Word2Vec trains a model of Map(String, Vector), i.e. transforms a word into a code for further natural language processing or machine learning process.

>>> sent = ("a b " * 100 + "a c " * 10).split(" ")
>>> doc = spark.createDataFrame([(sent,), (sent,)], ["sentence"])
>>> word2Vec = Word2Vec(vectorSize=5, seed=42, inputCol="sentence", outputCol="model")
>>> word2Vec.setMaxIter(10)
Word2Vec...
>>> word2Vec.getMaxIter()
10
>>> word2Vec.clear(word2Vec.maxIter)
>>> model = word2Vec.fit(doc)
>>> model.getMinCount()
5
>>> model.setInputCol("sentence")
Word2VecModel...
>>> model.getVectors().show()
+----+--------------------+
|word|              vector|
+----+--------------------+
|   a|[0.09511678665876...|
|   b|[-1.2028766870498...|
|   c|[0.30153277516365...|
+----+--------------------+
...
>>> model.findSynonymsArray("a", 2)
[('b', 0.015859870240092278), ('c', -0.5680795907974243)]
>>> from pyspark.sql.functions import format_number as fmt
>>> model.findSynonyms("a", 2).select("word", fmt("similarity", 5).alias("similarity")).show()
+----+----------+
|word|similarity|
+----+----------+
|   b|   0.01586|
|   c|  -0.56808|
+----+----------+
...
>>> model.transform(doc).head().model
DenseVector([-0.4833, 0.1855, -0.273, -0.0509, -0.4769])
>>> word2vecPath = temp_path + "/word2vec"
>>> word2Vec.save(word2vecPath)
>>> loadedWord2Vec = Word2Vec.load(word2vecPath)
>>> loadedWord2Vec.getVectorSize() == word2Vec.getVectorSize()
True
>>> loadedWord2Vec.getNumPartitions() == word2Vec.getNumPartitions()
True
>>> loadedWord2Vec.getMinCount() == word2Vec.getMinCount()
True
>>> modelPath = temp_path + "/word2vec-model"
>>> model.save(modelPath)
>>> loadedModel = Word2VecModel.load(modelPath)
>>> loadedModel.getVectors().first().word == model.getVectors().first().word
True
>>> loadedModel.getVectors().first().vector == model.getVectors().first().vector
True

New in version 1.4.0.

Methods

Attributes

Methods Documentation

clear(param)

Clears a param from the param map if it has been explicitly set.

copy(extra=None)

Creates a copy of this instance with the same uid and some extra params. This implementation first calls Params.copy and then make a copy of the companion Java pipeline component with extra params. So both the Python wrapper and the Java pipeline component get copied.

Parameters

extra – Extra parameters to copy to the new instance

Returns

Copy of this instance

explainParam(param)

Explains a single param and returns its name, doc, and optional default value and user-supplied value in a string.

explainParams()

Returns the documentation of all params with their optionally default values and user-supplied values.

extractParamMap(extra=None)

Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values < user-supplied values < extra.

Parameters

extra – extra param values

Returns

merged param map

fit(dataset, params=None)

Fits a model to the input dataset with optional parameters.

Parameters
  • dataset – input dataset, which is an instance of pyspark.sql.DataFrame

  • params – an optional param map that overrides embedded params. If a list/tuple of param maps is given, this calls fit on each param map and returns a list of models.

Returns

fitted model(s)

New in version 1.3.0.

fitMultiple(dataset, paramMaps)

Fits a model to the input dataset for each param map in paramMaps.

Parameters
  • dataset – input dataset, which is an instance of pyspark.sql.DataFrame.

  • paramMaps – A Sequence of param maps.

Returns

A thread safe iterable which contains one model for each param map. Each call to next(modelIterator) will return (index, model) where model was fit using paramMaps[index]. index values may not be sequential.

New in version 2.3.0.

getInputCol()

Gets the value of inputCol or its default value.

getMaxIter()

Gets the value of maxIter or its default value.

getMaxSentenceLength()

Gets the value of maxSentenceLength or its default value.

New in version 2.0.0.

getMinCount()

Gets the value of minCount or its default value.

New in version 1.4.0.

getNumPartitions()

Gets the value of numPartitions or its default value.

New in version 1.4.0.

getOrDefault(param)

Gets the value of a param in the user-supplied param map or its default value. Raises an error if neither is set.

getOutputCol()

Gets the value of outputCol or its default value.

getParam(paramName)

Gets a param by its name.

getSeed()

Gets the value of seed or its default value.

getStepSize()

Gets the value of stepSize or its default value.

getVectorSize()

Gets the value of vectorSize or its default value.

New in version 1.4.0.

getWindowSize()

Gets the value of windowSize or its default value.

New in version 2.0.0.

hasDefault(param)

Checks whether a param has a default value.

hasParam(paramName)

Tests whether this instance contains a param with a given (string) name.

isDefined(param)

Checks whether a param is explicitly set by user or has a default value.

isSet(param)

Checks whether a param is explicitly set by user.

classmethod load(path)

Reads an ML instance from the input path, a shortcut of read().load(path).

classmethod read()

Returns an MLReader instance for this class.

save(path)

Save this ML instance to the given path, a shortcut of ‘write().save(path)’.

set(param, value)

Sets a parameter in the embedded param map.

setInputCol(value)[source]

Sets the value of inputCol.

setMaxIter(value)[source]

Sets the value of maxIter.

setMaxSentenceLength(value)[source]

Sets the value of maxSentenceLength.

New in version 2.0.0.

setMinCount(value)[source]

Sets the value of minCount.

New in version 1.4.0.

setNumPartitions(value)[source]

Sets the value of numPartitions.

New in version 1.4.0.

setOutputCol(value)[source]

Sets the value of outputCol.

setParams(self, minCount=5, numPartitions=1, stepSize=0.025, maxIter=1, seed=None, inputCol=None, outputCol=None, windowSize=5, maxSentenceLength=1000)[source]

Sets params for this Word2Vec.

New in version 1.4.0.

setSeed(value)[source]

Sets the value of seed.

setStepSize(value)[source]

Sets the value of stepSize.

New in version 1.4.0.

setVectorSize(value)[source]

Sets the value of vectorSize.

New in version 1.4.0.

setWindowSize(value)[source]

Sets the value of windowSize.

New in version 2.0.0.

write()

Returns an MLWriter instance for this ML instance.

Attributes Documentation

inputCol = Param(parent='undefined', name='inputCol', doc='input column name.')
maxIter = Param(parent='undefined', name='maxIter', doc='max number of iterations (>= 0).')
maxSentenceLength = Param(parent='undefined', name='maxSentenceLength', doc='Maximum length (in words) of each sentence in the input data. Any sentence longer than this threshold will be divided into chunks up to the size.')
minCount = Param(parent='undefined', name='minCount', doc="the minimum number of times a token must appear to be included in the word2vec model's vocabulary")
numPartitions = Param(parent='undefined', name='numPartitions', doc='number of partitions for sentences of words')
outputCol = Param(parent='undefined', name='outputCol', doc='output column name.')
params

Returns all params ordered by name. The default implementation uses dir() to get all attributes of type Param.

seed = Param(parent='undefined', name='seed', doc='random seed.')
stepSize = Param(parent='undefined', name='stepSize', doc='Step size to be used for each iteration of optimization (>= 0).')
vectorSize = Param(parent='undefined', name='vectorSize', doc='the dimension of codes after transforming from words')
windowSize = Param(parent='undefined', name='windowSize', doc='the window size (context words from [-window, window]). Default value is 5')