org.apache.spark.ml.feature

Class StringIndexer

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, StringIndexerBase, Params, HasHandleInvalid, HasInputCol, HasOutputCol, DefaultParamsWritable, Identifiable, MLWritable

public class StringIndexer
extends Estimator<StringIndexerModel>
implements StringIndexerBase, DefaultParamsWritable

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). By default, this is ordered by label frequencies so the most frequent label gets index 0. The ordering behavior is controlled by setting stringOrderType.

See Also:

IndexToString for the inverse transformation, Serialized Form

Constructor Summary

Constructors

Constructor and Description
StringIndexer()
StringIndexer(String uid)

Method Summary

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(Dataset<?> dataset) Fits a model to the input data.
static StringIndexer	load(String path)
static MLReader<T>	read()
StringIndexer	setHandleInvalid(String value)
StringIndexer	setInputCol(String value)
StringIndexer	setOutputCol(String value)
StringIndexer	setStringOrderType(String value)
StructType	transformSchema(StructType schema) :: DeveloperApi ::
String	uid() An immutable unique ID for the object and its derivatives.

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

fit, fit, fit, fit

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.ml.feature.StringIndexerBase

getStringOrderType, handleInvalid, stringOrderType, validateAndTransformSchema

Methods inherited from interface org.apache.spark.ml.param.shared.HasHandleInvalid

getHandleInvalid

Methods inherited from interface org.apache.spark.ml.param.shared.HasInputCol

getInputCol, inputCol

Methods inherited from interface org.apache.spark.ml.param.shared.HasOutputCol

getOutputCol, outputCol

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

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

toString

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

write

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

save

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

StringIndexer

public StringIndexer(String uid)

StringIndexer

public StringIndexer()

Method Detail

load

public static StringIndexer load(String path)

read

public static MLReader<T> read()

uid

public 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)

setHandleInvalid

public StringIndexer setHandleInvalid(String value)

setStringOrderType

public StringIndexer setStringOrderType(String value)

setInputCol

public StringIndexer setInputCol(String value)

setOutputCol

public StringIndexer setOutputCol(String value)

fit

public StringIndexerModel fit(Dataset<?> 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 ::

Check transform validity and derive the output schema from the input schema.

We check validity for interactions between parameters during transformSchema and raise an exception if any parameter value is invalid. Parameter value checks which do not depend on other parameters are handled by Param.validate().

Typical implementation should first conduct verification on schema change and parameter validity, including complex parameter interaction checks.

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. See defaultCopy().

Specified by:

copy in interface Params

Specified by:

copy in class Estimator<StringIndexerModel>

Parameters:

extra - (undocumented)

Returns:

(undocumented)