FPGrowth¶

class pyspark.ml.fpm.FPGrowth(*, minSupport=0.3, minConfidence=0.8, itemsCol='items', predictionCol='prediction', numPartitions=None)[source]¶

A parallel FP-growth algorithm to mine frequent itemsets.

New in version 2.2.0.

Notes

The algorithm is described in Li et al., PFP: Parallel FP-Growth for Query Recommendation [1]. PFP distributes computation in such a way that each worker executes an independent group of mining tasks. The FP-Growth algorithm is described in Han et al., Mining frequent patterns without candidate generation [2]

NULL values in the feature column are ignored during fit().

Internally transform collects and broadcasts association rules.

[1]

Haoyuan Li, Yi Wang, Dong Zhang, Ming Zhang, and Edward Y. Chang. 2008. Pfp: parallel fp-growth for query recommendation. In Proceedings of the 2008 ACM conference on Recommender systems (RecSys ‘08). Association for Computing Machinery, New York, NY, USA, 107–114. DOI: https://doi.org/10.1145/1454008.1454027

[2]

Jiawei Han, Jian Pei, and Yiwen Yin. 2000. Mining frequent patterns without candidate generation. SIGMOD Rec. 29, 2 (June 2000), 1–12. DOI: https://doi.org/10.1145/335191.335372

Examples

>>> from pyspark.sql.functions import split
>>> data = (spark.read
...     .text("data/mllib/sample_fpgrowth.txt")
...     .select(split("value", "\s+").alias("items")))
>>> data.show(truncate=False)
+------------------------+
|items                   |
+------------------------+
|[r, z, h, k, p]         |
|[z, y, x, w, v, u, t, s]|
|[s, x, o, n, r]         |
|[x, z, y, m, t, s, q, e]|
|[z]                     |
|[x, z, y, r, q, t, p]   |
+------------------------+
...
>>> fp = FPGrowth(minSupport=0.2, minConfidence=0.7)
>>> fpm = fp.fit(data)
>>> fpm.setPredictionCol("newPrediction")
FPGrowthModel...
>>> fpm.freqItemsets.show(5)
+---------+----+
|    items|freq|
+---------+----+
|      [s]|   3|
|   [s, x]|   3|
|[s, x, z]|   2|
|   [s, z]|   2|
|      [r]|   3|
+---------+----+
only showing top 5 rows
...
>>> fpm.associationRules.show(5)
+----------+----------+----------+----+------------------+
|antecedent|consequent|confidence|lift|           support|
+----------+----------+----------+----+------------------+
|    [t, s]|       [y]|       1.0| 2.0|0.3333333333333333|
|    [t, s]|       [x]|       1.0| 1.5|0.3333333333333333|
|    [t, s]|       [z]|       1.0| 1.2|0.3333333333333333|
|       [p]|       [r]|       1.0| 2.0|0.3333333333333333|
|       [p]|       [z]|       1.0| 1.2|0.3333333333333333|
+----------+----------+----------+----+------------------+
only showing top 5 rows
...
>>> new_data = spark.createDataFrame([(["t", "s"], )], ["items"])
>>> sorted(fpm.transform(new_data).first().newPrediction)
['x', 'y', 'z']
>>> model_path = temp_path + "/fpm_model"
>>> fpm.save(model_path)
>>> model2 = FPGrowthModel.load(model_path)
>>> fpm.transform(data).take(1) == model2.transform(data).take(1)
True

Methods

`clear`(param)	Clears a param from the param map if it has been explicitly set.
`copy`([extra])	Creates a copy of this instance with the same uid and some extra params.
`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])	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.
`fit`(dataset[, params])	Fits a model to the input dataset with optional parameters.
`fitMultiple`(dataset, paramMaps)	Fits a model to the input dataset for each param map in paramMaps.
`getItemsCol`()	Gets the value of itemsCol or its default value.
`getMinConfidence`()	Gets the value of minConfidence or its default value.
`getMinSupport`()	Gets the value of minSupport or its default value.
`getNumPartitions`()	Gets the value of `numPartitions` or its default value.
`getOrDefault`(param)	Gets the value of a param in the user-supplied param map or its default value.
`getParam`(paramName)	Gets a param by its name.
`getPredictionCol`()	Gets the value of predictionCol or its default value.
`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.
`load`(path)	Reads an ML instance from the input path, a shortcut of read().load(path).
`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.
`setItemsCol`(value)	Sets the value of `itemsCol`.
`setMinConfidence`(value)	Sets the value of `minConfidence`.
`setMinSupport`(value)	Sets the value of `minSupport`.
`setNumPartitions`(value)	Sets the value of `numPartitions`.
`setParams`(self, \*[, minSupport, …])	New in version 2.2.0.
`setPredictionCol`(value)	Sets the value of `predictionCol`.
`write`()	Returns an MLWriter instance for this ML instance.

Attributes

`itemsCol`
`minConfidence`
`minSupport`
`numPartitions`
`params`	Returns all params ordered by name.
`predictionCol`

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:

extradict, optional: Extra parameters to copy to the new instance

Returns:

JavaParams: 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:

extradict, optional: extra param values

Returns:

dict: merged param map

fit(dataset, params=None)¶

Fits a model to the input dataset with optional parameters.

New in version 1.3.0.

Parameters:

datasetpyspark.sql.DataFrame: input dataset.
paramsdict or list or tuple, optional: 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:

Transformer or a list of Transformer: fitted model(s)

fitMultiple(dataset, paramMaps)¶

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

New in version 2.3.0.

Parameters:

datasetpyspark.sql.DataFrame: input dataset.
paramMapscollections.abc.Sequence: A Sequence of param maps.

Returns:

_FitMultipleIterator: 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.

getItemsCol()¶: Gets the value of itemsCol or its default value.

getMinConfidence()¶: Gets the value of minConfidence or its default value.

getMinSupport()¶: Gets the value of minSupport or its default value.

getNumPartitions()¶: Gets the value of numPartitions or its default value.

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.

getParam(paramName)¶: Gets a param by its name.

getPredictionCol()¶: Gets the value of predictionCol or its default value.

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.

setItemsCol(value)[source]¶: Sets the value of itemsCol.

setMinConfidence(value)[source]¶: Sets the value of minConfidence.

setMinSupport(value)[source]¶: Sets the value of minSupport.

setNumPartitions(value)[source]¶: Sets the value of numPartitions.

setParams(self, \*, minSupport=0.3, minConfidence=0.8, itemsCol="items", predictionCol="prediction", numPartitions=None)[source]¶: New in version 2.2.0.

setPredictionCol(value)[source]¶: Sets the value of predictionCol.

write()¶: Returns an MLWriter instance for this ML instance.

Attributes Documentation

itemsCol = Param(parent='undefined', name='itemsCol', doc='items column name')¶

minConfidence = Param(parent='undefined', name='minConfidence', doc='Minimal confidence for generating Association Rule. [0.0, 1.0]. minConfidence will not affect the mining for frequent itemsets, but will affect the association rules generation.')¶

minSupport = Param(parent='undefined', name='minSupport', doc='Minimal support level of the frequent pattern. [0.0, 1.0]. Any pattern that appears more than (minSupport * size-of-the-dataset) times will be output in the frequent itemsets.')¶

numPartitions = Param(parent='undefined', name='numPartitions', doc='Number of partitions (at least 1) used by parallel FP-growth. By default the param is not set, and partition number of the input dataset is used.')¶

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

predictionCol = Param(parent='undefined', name='predictionCol', doc='prediction column name.')¶

RankingEvaluator FPGrowthModel