org.apache.spark.ml.evaluation

Class ClusteringEvaluator

Object

org.apache.spark.ml.evaluation.Evaluator

org.apache.spark.ml.evaluation.ClusteringEvaluator

All Implemented Interfaces:

java.io.Serializable, Params, HasFeaturesCol, HasPredictionCol, HasWeightCol, DefaultParamsWritable, Identifiable, MLWritable

public class ClusteringEvaluator
extends Evaluator
implements HasPredictionCol, HasFeaturesCol, HasWeightCol, DefaultParamsWritable

Evaluator for clustering results. The metric computes the Silhouette measure using the specified distance measure.

The Silhouette is a measure for the validation of the consistency within clusters. It ranges between 1 and -1, where a value close to 1 means that the points in a cluster are close to the other points in the same cluster and far from the points of the other clusters.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ClusteringEvaluator()
ClusteringEvaluator(String uid)

Method Summary

Modifier and Type	Method and Description
ClusteringEvaluator	copy(ParamMap pMap) Creates a copy of this instance with the same UID and some extra params.
Param<String>	distanceMeasure() param for distance measure to be used in evaluation (supports "squaredEuclidean" (default), "cosine")
double	evaluate(Dataset<?> dataset) Evaluates model output and returns a scalar metric.
Param<String>	featuresCol() Param for features column name.
String	getDistanceMeasure()
String	getMetricName()
ClusteringMetrics	getMetrics(Dataset<?> dataset) Get a ClusteringMetrics, which can be used to get clustering metrics such as silhouette score.
boolean	isLargerBetter() Indicates whether the metric returned by evaluate should be maximized (true, default) or minimized (false).
static ClusteringEvaluator	load(String path)
Param<String>	metricName() param for metric name in evaluation (supports "silhouette" (default))
Param<String>	predictionCol() Param for prediction column name.
static MLReader<T>	read()
ClusteringEvaluator	setDistanceMeasure(String value)
ClusteringEvaluator	setFeaturesCol(String value)
ClusteringEvaluator	setMetricName(String value)
ClusteringEvaluator	setPredictionCol(String value)
ClusteringEvaluator	setWeightCol(String value)
String	toString()
String	uid() An immutable unique ID for the object and its derivatives.
Param<String>	weightCol() Param for weight column name.

Methods inherited from class org.apache.spark.ml.evaluation.Evaluator

evaluate, params

Methods inherited from class Object

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

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

getPredictionCol

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

getFeaturesCol

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

getWeightCol

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, onParamChange, paramMap, params, set, set, set, setDefault, setDefault, shouldOwn

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

write

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

save

Constructor Detail

ClusteringEvaluator

public ClusteringEvaluator(String uid)

ClusteringEvaluator

public ClusteringEvaluator()

Method Detail

load

public static ClusteringEvaluator load(String path)

read

public static MLReader<T> read()

weightCol

public final Param<String> weightCol()

Description copied from interface: HasWeightCol

Param for weight column name. If this is not set or empty, we treat all instance weights as 1.0.

Specified by:

weightCol in interface HasWeightCol

Returns:

(undocumented)

featuresCol

public final Param<String> featuresCol()

Description copied from interface: HasFeaturesCol

Param for features column name.

Specified by:

featuresCol in interface HasFeaturesCol

Returns:

(undocumented)

predictionCol

public final Param<String> predictionCol()

Description copied from interface: HasPredictionCol

Param for prediction column name.

Specified by:

predictionCol in interface HasPredictionCol

Returns:

(undocumented)

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)

copy

public ClusteringEvaluator copy(ParamMap pMap)

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 Evaluator

Parameters:

pMap - (undocumented)

Returns:

(undocumented)

isLargerBetter

public boolean isLargerBetter()

Description copied from class: Evaluator

Indicates whether the metric returned by evaluate should be maximized (true, default) or minimized (false). A given evaluator may support multiple metrics which may be maximized or minimized.

Overrides:

isLargerBetter in class Evaluator

Returns:

(undocumented)

setPredictionCol

public ClusteringEvaluator setPredictionCol(String value)

setFeaturesCol

public ClusteringEvaluator setFeaturesCol(String value)

setWeightCol

public ClusteringEvaluator setWeightCol(String value)

metricName

public Param<String> metricName()

param for metric name in evaluation (supports "silhouette" (default))

Returns:

(undocumented)

getMetricName

public String getMetricName()

setMetricName

public ClusteringEvaluator setMetricName(String value)

distanceMeasure

public Param<String> distanceMeasure()

param for distance measure to be used in evaluation (supports "squaredEuclidean" (default), "cosine")

Returns:

(undocumented)

getDistanceMeasure

public String getDistanceMeasure()

setDistanceMeasure

public ClusteringEvaluator setDistanceMeasure(String value)

evaluate

public double evaluate(Dataset<?> dataset)

Description copied from class: Evaluator

Evaluates model output and returns a scalar metric. The value of isLargerBetter specifies whether larger values are better.

Specified by:

evaluate in class Evaluator

Parameters:

dataset - a dataset that contains labels/observations and predictions.

Returns:

metric

getMetrics

public ClusteringMetrics getMetrics(Dataset<?> dataset)

Get a ClusteringMetrics, which can be used to get clustering metrics such as silhouette score.

Parameters:

dataset - a dataset that contains labels/observations and predictions.

Returns:

ClusteringMetrics

toString

public String toString()

Specified by:

toString in interface Identifiable

Overrides:

toString in class Object