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, Params, DefaultParamsWritable, Identifiable, MLWritable

public class StringIndexer
extends Estimator<StringIndexerModel>
implements 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), 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(String uid)

Method Summary

Methods

Modifier and Type	Method and Description
static Params	clear(Param<?> param)
StringIndexer	copy(ParamMap extra) Creates a copy of this instance with the same UID and some extra params.
static String	explainParam(Param<?> param)
static String	explainParams()
static ParamMap	extractParamMap()
static ParamMap	extractParamMap(ParamMap extra)
StringIndexerModel	fit(Dataset<?> dataset) Fits a model to the input data.
static <T> scala.Option<T>	get(Param<T> param)
static <T> scala.Option<T>	getDefault(Param<T> param)
static String	getHandleInvalid()
String	getHandleInvalid()
static String	getInputCol()
String	getInputCol()
static <T> T	getOrDefault(Param<T> param)
static String	getOutputCol()
String	getOutputCol()
static Param<Object>	getParam(String paramName)
static Param<String>	handleInvalid()
Param<String>	handleInvalid() Param for how to handle invalid entries.
static <T> boolean	hasDefault(Param<T> param)
static boolean	hasParam(String paramName)
static Param<String>	inputCol()
Param<String>	inputCol() Param for input column name.
static boolean	isDefined(Param<?> param)
static boolean	isSet(Param<?> param)
static StringIndexer	load(String path)
static Param<String>	outputCol()
Param<String>	outputCol() Param for output column name.
static Param<?>[]	params()
static void	save(String path)
static <T> Params	set(Param<T> param, T value)
StringIndexer	setHandleInvalid(String value)
StringIndexer	setInputCol(String value)
StringIndexer	setOutputCol(String value)
static String	toString()
StructType	transformSchema(StructType schema) :: DeveloperApi ::
String	uid() An immutable unique ID for the object and its derivatives.
StructType	validateAndTransformSchema(StructType schema) Validates and transforms the input schema.
static void	validateParams()
static MLWriter	write()

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.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.ml.util.DefaultParamsWritable

write

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

save

Constructor Detail

StringIndexer

public StringIndexer(String uid)

StringIndexer

public StringIndexer()

Method Detail

load

public static StringIndexer load(String path)

toString

public static String toString()

params

public static Param<?>[] params()

validateParams

public static void validateParams()

explainParam

public static String explainParam(Param<?> param)

explainParams

public static String explainParams()

isSet

public static final boolean isSet(Param<?> param)

isDefined

public static final boolean isDefined(Param<?> param)

hasParam

public static boolean hasParam(String paramName)

getParam

public static Param<Object> getParam(String paramName)

set

public static final <T> Params set(Param<T> param,
             T value)

get

public static final <T> scala.Option<T> get(Param<T> param)

clear

public static final Params clear(Param<?> param)

getOrDefault

public static final <T> T getOrDefault(Param<T> param)

getDefault

public static final <T> scala.Option<T> getDefault(Param<T> param)

hasDefault

public static final <T> boolean hasDefault(Param<T> param)

extractParamMap

public static final ParamMap extractParamMap(ParamMap extra)

extractParamMap

public static final ParamMap extractParamMap()

inputCol

public static final Param<String> inputCol()

getInputCol

public static final String getInputCol()

outputCol

public static final Param<String> outputCol()

getOutputCol

public static final String getOutputCol()

handleInvalid

public static final Param<String> handleInvalid()

getHandleInvalid

public static final String getHandleInvalid()

save

public static void save(String path)
                 throws java.io.IOException

Throws:

java.io.IOException

write

public static MLWriter write()

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)

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.

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)

validateAndTransformSchema

public StructType validateAndTransformSchema(StructType schema)

Validates and transforms the input schema.

inputCol

public Param<String> inputCol()

Param for input column name.

Returns:

(undocumented)

getInputCol

public String getInputCol()

outputCol

public Param<String> outputCol()

Param for output column name.

Returns:

(undocumented)

getOutputCol

public String getOutputCol()

handleInvalid

public Param<String> handleInvalid()

Param for how to handle invalid entries. Options are skip (which will filter out rows with bad values), or error (which will throw an error). More options may be added later.

Returns:

(undocumented)

getHandleInvalid

public String getHandleInvalid()