RFormula¶
-
class
pyspark.ml.feature.
RFormula
(formula=None, featuresCol='features', labelCol='label', forceIndexLabel=False, stringIndexerOrderType='frequencyDesc', handleInvalid='error')[source]¶ Implements the transforms required for fitting a dataset against an R model formula. Currently we support a limited subset of the R operators, including ‘~’, ‘.’, ‘:’, ‘+’, ‘-‘, ‘*’, and ‘^’. Also see the R formula docs.
>>> df = spark.createDataFrame([ ... (1.0, 1.0, "a"), ... (0.0, 2.0, "b"), ... (0.0, 0.0, "a") ... ], ["y", "x", "s"]) >>> rf = RFormula(formula="y ~ x + s") >>> model = rf.fit(df) >>> model.getLabelCol() 'label' >>> model.transform(df).show() +---+---+---+---------+-----+ | y| x| s| features|label| +---+---+---+---------+-----+ |1.0|1.0| a|[1.0,1.0]| 1.0| |0.0|2.0| b|[2.0,0.0]| 0.0| |0.0|0.0| a|[0.0,1.0]| 0.0| +---+---+---+---------+-----+ ... >>> rf.fit(df, {rf.formula: "y ~ . - s"}).transform(df).show() +---+---+---+--------+-----+ | y| x| s|features|label| +---+---+---+--------+-----+ |1.0|1.0| a| [1.0]| 1.0| |0.0|2.0| b| [2.0]| 0.0| |0.0|0.0| a| [0.0]| 0.0| +---+---+---+--------+-----+ ... >>> rFormulaPath = temp_path + "/rFormula" >>> rf.save(rFormulaPath) >>> loadedRF = RFormula.load(rFormulaPath) >>> loadedRF.getFormula() == rf.getFormula() True >>> loadedRF.getFeaturesCol() == rf.getFeaturesCol() True >>> loadedRF.getLabelCol() == rf.getLabelCol() True >>> loadedRF.getHandleInvalid() == rf.getHandleInvalid() True >>> str(loadedRF) 'RFormula(y ~ x + s) (uid=...)' >>> modelPath = temp_path + "/rFormulaModel" >>> model.save(modelPath) >>> loadedModel = RFormulaModel.load(modelPath) >>> loadedModel.uid == model.uid True >>> loadedModel.transform(df).show() +---+---+---+---------+-----+ | y| x| s| features|label| +---+---+---+---------+-----+ |1.0|1.0| a|[1.0,1.0]| 1.0| |0.0|2.0| b|[2.0,0.0]| 0.0| |0.0|0.0| a|[0.0,1.0]| 0.0| +---+---+---+---------+-----+ ... >>> str(loadedModel) 'RFormulaModel(ResolvedRFormula(label=y, terms=[x,s], hasIntercept=true)) (uid=...)'
New in version 1.5.0.
Methods
Attributes
Methods Documentation
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clear
(param)¶ Clears a param from the param map if it has been explicitly set.
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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
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explainParam
(param)¶ Explains a single param and returns its name, doc, and optional default value and user-supplied value in a string.
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explainParams
()¶ Returns the documentation of all params with their optionally default values and user-supplied values.
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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
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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.
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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.
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getFeaturesCol
()¶ Gets the value of featuresCol or its default value.
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getForceIndexLabel
()¶ Gets the value of
forceIndexLabel
.New in version 2.1.0.
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getHandleInvalid
()¶ Gets the value of handleInvalid or its default value.
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getLabelCol
()¶ Gets the value of labelCol or its default value.
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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.
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getParam
(paramName)¶ Gets a param by its name.
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getStringIndexerOrderType
()¶ Gets the value of
stringIndexerOrderType
or its default value ‘frequencyDesc’.New in version 2.3.0.
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hasDefault
(param)¶ Checks whether a param has a default value.
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hasParam
(paramName)¶ Tests whether this instance contains a param with a given (string) name.
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isDefined
(param)¶ Checks whether a param is explicitly set by user or has a default value.
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isSet
(param)¶ Checks whether a param is explicitly set by user.
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classmethod
load
(path)¶ Reads an ML instance from the input path, a shortcut of read().load(path).
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classmethod
read
()¶ Returns an MLReader instance for this class.
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save
(path)¶ Save this ML instance to the given path, a shortcut of ‘write().save(path)’.
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set
(param, value)¶ Sets a parameter in the embedded param map.
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setFeaturesCol
(value)[source]¶ Sets the value of
featuresCol
.
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setForceIndexLabel
(value)[source]¶ Sets the value of
forceIndexLabel
.New in version 2.1.0.
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setHandleInvalid
(value)[source]¶ Sets the value of
handleInvalid
.
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setParams
(self, formula=None, featuresCol='features', labelCol='label', forceIndexLabel=False, stringIndexerOrderType='frequencyDesc', handleInvalid='error')[source]¶ Sets params for RFormula.
New in version 1.5.0.
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setStringIndexerOrderType
(value)[source]¶ Sets the value of
stringIndexerOrderType
.New in version 2.3.0.
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write
()¶ Returns an MLWriter instance for this ML instance.
Attributes Documentation
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featuresCol
= Param(parent='undefined', name='featuresCol', doc='features column name.')¶
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forceIndexLabel
= Param(parent='undefined', name='forceIndexLabel', doc='Force to index label whether it is numeric or string')¶
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formula
= Param(parent='undefined', name='formula', doc='R model formula')¶
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handleInvalid
= Param(parent='undefined', name='handleInvalid', doc="how to handle invalid entries. Options are 'skip' (filter out rows with invalid values), 'error' (throw an error), or 'keep' (put invalid data in a special additional bucket, at index numLabels).")¶
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labelCol
= Param(parent='undefined', name='labelCol', doc='label column name.')¶
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params
¶ Returns all params ordered by name. The default implementation uses
dir()
to get all attributes of typeParam
.
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stringIndexerOrderType
= Param(parent='undefined', name='stringIndexerOrderType', doc='How to order categories of a string feature column used by StringIndexer. The last category after ordering is dropped when encoding strings. Supported options: frequencyDesc, frequencyAsc, alphabetDesc, alphabetAsc. The default value is frequencyDesc. When the ordering is set to alphabetDesc, RFormula drops the same category as R when encoding strings.')¶
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