org.apache.spark.ml.feature

Class StandardScaler

Object

org.apache.spark.ml.PipelineStage

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

org.apache.spark.ml.feature.StandardScaler

All Implemented Interfaces:

java.io.Serializable, Logging, Params, DefaultParamsWritable, Identifiable, MLWritable

public class StandardScaler
extends Estimator<StandardScalerModel>
implements DefaultParamsWritable

Standardizes features by removing the mean and scaling to unit variance using column summary statistics on the samples in the training set.

The "unit std" is computed using the corrected sample standard deviation, which is computed as the square root of the unbiased sample variance.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
StandardScaler()
StandardScaler(String uid)

Method Summary

Modifier and Type	Method and Description
static Params	clear(Param<?> param)
StandardScaler	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)
StandardScalerModel	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	getInputCol()
static <T> T	getOrDefault(Param<T> param)
static String	getOutputCol()
static Param<Object>	getParam(String paramName)
static boolean	getWithMean()
boolean	getWithMean()
static boolean	getWithStd()
boolean	getWithStd()
static <T> boolean	hasDefault(Param<T> param)
static boolean	hasParam(String paramName)
static Param<String>	inputCol()
static boolean	isDefined(Param<?> param)
static boolean	isSet(Param<?> param)
static StandardScaler	load(String path)
static Param<String>	outputCol()
static Param<?>[]	params()
static void	save(String path)
static <T> Params	set(Param<T> param, T value)
StandardScaler	setInputCol(String value)
StandardScaler	setOutputCol(String value)
StandardScaler	setWithMean(boolean value)
StandardScaler	setWithStd(boolean 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 BooleanParam	withMean()
BooleanParam	withMean() Whether to center the data with mean before scaling.
static BooleanParam	withStd()
BooleanParam	withStd() Whether to scale the data to unit standard deviation.
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.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

StandardScaler

public StandardScaler(String uid)

StandardScaler

public StandardScaler()

Method Detail

load

public static StandardScaler load(String path)

toString

public static String toString()

params

public static Param<?>[] params()

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()

withMean

public static BooleanParam withMean()

getWithMean

public static boolean getWithMean()

withStd

public static BooleanParam withStd()

getWithStd

public static boolean getWithStd()

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)

setInputCol

public StandardScaler setInputCol(String value)

setOutputCol

public StandardScaler setOutputCol(String value)

setWithMean

public StandardScaler setWithMean(boolean value)

setWithStd

public StandardScaler setWithStd(boolean value)

fit

public StandardScalerModel fit(Dataset<?> dataset)

Description copied from class: Estimator

Fits a model to the input data.

Specified by:

fit in class Estimator<StandardScalerModel>

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 StandardScaler 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<StandardScalerModel>

Parameters:

extra - (undocumented)

Returns:

(undocumented)

getWithMean

public boolean getWithMean()

getWithStd

public boolean getWithStd()

validateAndTransformSchema

public StructType validateAndTransformSchema(StructType schema)

Validates and transforms the input schema.

withMean

public BooleanParam withMean()

Whether to center the data with mean before scaling. It will build a dense output, so take care when applying to sparse input. Default: false

Returns:

(undocumented)

withStd

public BooleanParam withStd()

Whether to scale the data to unit standard deviation. Default: true

Returns:

(undocumented)