org.apache.spark.ml.tuning

Class CrossValidator

Object

org.apache.spark.ml.PipelineStage

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

org.apache.spark.ml.tuning.CrossValidator

All Implemented Interfaces:

java.io.Serializable, Params, Identifiable, MLWritable

public class CrossValidator
extends Estimator<CrossValidatorModel>
implements MLWritable

K-fold cross validation performs model selection by splitting the dataset into a set of non-overlapping randomly partitioned folds which are used as separate training and test datasets e.g., with k=3 folds, K-fold cross validation will generate 3 (training, test) dataset pairs, each of which uses 2/3 of the data for training and 1/3 for testing. Each fold is used as the test set exactly once.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CrossValidator()
CrossValidator(String uid)

Method Summary

Methods

Modifier and Type	Method and Description
static Params	clear(Param<?> param)
CrossValidator	copy(ParamMap extra) Creates a copy of this instance with the same UID and some extra params.
static Param<Estimator<?>>	estimator()
Param<Estimator<?>>	estimator() param for the estimator to be validated
static Param<ParamMap[]>	estimatorParamMaps()
Param<ParamMap[]>	estimatorParamMaps() param for estimator param maps
static Param<Evaluator>	evaluator()
Param<Evaluator>	evaluator() param for the evaluator used to select hyper-parameters that maximize the validated metric
static String	explainParam(Param<?> param)
static String	explainParams()
static ParamMap	extractParamMap()
static ParamMap	extractParamMap(ParamMap extra)
CrossValidatorModel	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 Estimator<?>	getEstimator()
Estimator<?>	getEstimator()
static ParamMap[]	getEstimatorParamMaps()
ParamMap[]	getEstimatorParamMaps()
static Evaluator	getEvaluator()
Evaluator	getEvaluator()
static int	getNumFolds()
int	getNumFolds()
static <T> T	getOrDefault(Param<T> param)
static Param<Object>	getParam(String paramName)
static long	getSeed()
static <T> boolean	hasDefault(Param<T> param)
static boolean	hasParam(String paramName)
static boolean	isDefined(Param<?> param)
static boolean	isSet(Param<?> param)
static CrossValidator	load(String path)
static IntParam	numFolds()
IntParam	numFolds() Param for number of folds for cross validation.
static Param<?>[]	params()
static MLReader<CrossValidator>	read()
static void	save(String path)
static LongParam	seed()
static <T> Params	set(Param<T> param, T value)
CrossValidator	setEstimator(Estimator<?> value)
CrossValidator	setEstimatorParamMaps(ParamMap[] value)
CrossValidator	setEvaluator(Evaluator value)
CrossValidator	setNumFolds(int value)
CrossValidator	setSeed(long value)
static String	toString()
StructType	transformSchema(StructType schema) :: DeveloperApi ::
StructType	transformSchemaImpl(StructType schema)
String	uid() An immutable unique ID for the object and its derivatives.
MLWriter	write() Returns an MLWriter instance for this ML instance.

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

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

toString

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

save

Constructor Detail

CrossValidator

public CrossValidator(String uid)

CrossValidator

public CrossValidator()

Method Detail

read

public static MLReader<CrossValidator> read()

load

public static CrossValidator 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()

seed

public static final LongParam seed()

getSeed

public static final long getSeed()

estimator

public static Param<Estimator<?>> estimator()

getEstimator

public static Estimator<?> getEstimator()

estimatorParamMaps

public static Param<ParamMap[]> estimatorParamMaps()

getEstimatorParamMaps

public static ParamMap[] getEstimatorParamMaps()

evaluator

public static Param<Evaluator> evaluator()

getEvaluator

public static Evaluator getEvaluator()

numFolds

public static IntParam numFolds()

getNumFolds

public static int getNumFolds()

save

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

Throws:

java.io.IOException

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)

setEstimator

public CrossValidator setEstimator(Estimator<?> value)

setEstimatorParamMaps

public CrossValidator setEstimatorParamMaps(ParamMap[] value)

setEvaluator

public CrossValidator setEvaluator(Evaluator value)

setNumFolds

public CrossValidator setNumFolds(int value)

setSeed

public CrossValidator setSeed(long value)

fit

public CrossValidatorModel fit(Dataset<?> dataset)

Description copied from class: Estimator

Fits a model to the input data.

Specified by:

fit in class Estimator<CrossValidatorModel>

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 CrossValidator 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<CrossValidatorModel>

Parameters:

extra - (undocumented)

Returns:

(undocumented)

write

public MLWriter write()

Description copied from interface: MLWritable

Returns an MLWriter instance for this ML instance.

Specified by:

write in interface MLWritable

Returns:

(undocumented)

numFolds

public IntParam numFolds()

Param for number of folds for cross validation. Must be &gt;= 2. Default: 3

Returns:

(undocumented)

getNumFolds

public int getNumFolds()

estimator

public Param<Estimator<?>> estimator()

param for the estimator to be validated

Returns:

(undocumented)

getEstimator

public Estimator<?> getEstimator()

estimatorParamMaps

public Param<ParamMap[]> estimatorParamMaps()

param for estimator param maps

Returns:

(undocumented)

getEstimatorParamMaps

public ParamMap[] getEstimatorParamMaps()

evaluator

public Param<Evaluator> evaluator()

param for the evaluator used to select hyper-parameters that maximize the validated metric

Returns:

(undocumented)

getEvaluator

public Evaluator getEvaluator()

transformSchemaImpl

public StructType transformSchemaImpl(StructType schema)