org.apache.spark.ml.feature

Class StringIndexer

java.lang.Object

org.apache.spark.ml.PipelineStage

org.apache.spark.ml.Estimator<StringIndexerModel>

org.apache.spark.ml.feature.StringIndexer

All Implemented Interfaces:

java.io.Serializable, Logging, Params, Identifiable

public class StringIndexer
extends Estimator<StringIndexerModel>

:: Experimental :: A label indexer that maps a string column of labels to an ML column of label indices. If the input column is numeric, we cast it to string and index the string values. The indices are in [0, numLabels), ordered by label frequencies. So the most frequent label gets index 0.

See Also:

IndexToString} for the inverse transformation, Serialized Form

Constructor Summary

Constructors

Constructor and Description
StringIndexer()
StringIndexer(java.lang.String uid)

Method Summary

Methods

Modifier and Type	Method and Description
StringIndexer	copy(ParamMap extra) Creates a copy of this instance with the same UID and some extra params.
StringIndexerModel	fit(DataFrame dataset) Fits a model to the input data.
StringIndexer	setInputCol(java.lang.String value)
StringIndexer	setOutputCol(java.lang.String value)
StructType	transformSchema(StructType schema) :: DeveloperApi ::
java.lang.String	uid() An immutable unique ID for the object and its derivatives.
StructType	validateAndTransformSchema(StructType schema) Validates and transforms the input schema.

Methods inherited from class org.apache.spark.ml.Estimator

fit, fit, fit, fit

Methods inherited from class org.apache.spark.ml.PipelineStage

transformSchema

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.spark.ml.param.Params

clear, copyValues, defaultCopy, defaultParamMap, explainParam, explainParams, extractParamMap, extractParamMap, get, getDefault, getOrDefault, getParam, hasDefault, hasParam, isDefined, isSet, paramMap, params, set, set, set, setDefault, setDefault, shouldOwn, validateParams

Methods inherited from interface org.apache.spark.ml.util.Identifiable

toString

Methods inherited from interface org.apache.spark.Logging

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

Constructor Detail

StringIndexer

public StringIndexer(java.lang.String uid)

StringIndexer

public StringIndexer()

Method Detail

uid

public java.lang.String uid()

Description copied from interface: Identifiable

An immutable unique ID for the object and its derivatives.

Specified by:

uid in interface Identifiable

Returns:

(undocumented)

setInputCol

public StringIndexer setInputCol(java.lang.String value)

setOutputCol

public StringIndexer setOutputCol(java.lang.String value)

fit

public StringIndexerModel fit(DataFrame dataset)

Description copied from class: Estimator

Fits a model to the input data.

Specified by:

fit in class Estimator<StringIndexerModel>

Parameters:

dataset - (undocumented)

Returns:

(undocumented)

transformSchema

public StructType transformSchema(StructType schema)

Description copied from class: PipelineStage

:: DeveloperApi ::

Derives the output schema from the input schema.

Specified by:

transformSchema in class PipelineStage

Parameters:

schema - (undocumented)

Returns:

(undocumented)

copy

public StringIndexer copy(ParamMap extra)

Description copied from interface: Params

Creates a copy of this instance with the same UID and some extra params. Subclasses should implement this method and set the return type properly.

Specified by:

copy in interface Params

Specified by:

copy in class Estimator<StringIndexerModel>

Parameters:

extra - (undocumented)

Returns:

(undocumented)

See Also:

defaultCopy()

validateAndTransformSchema

public StructType validateAndTransformSchema(StructType schema)

Validates and transforms the input schema.