Package org.elasticsearch.index.rankeval

Class DiscountedCumulativeGain

java.lang.Object

org.elasticsearch.index.rankeval.DiscountedCumulativeGain

All Implemented Interfaces:

org.elasticsearch.common.io.stream.NamedWriteable, org.elasticsearch.common.io.stream.Writeable, org.elasticsearch.common.xcontent.ToXContent, org.elasticsearch.common.xcontent.ToXContentObject, EvaluationMetric

public class DiscountedCumulativeGain
extends java.lang.Object
implements EvaluationMetric

Metric implementing Discounted Cumulative Gain. The `normalize` parameter can be set to calculate the normalized NDCG (set to false by default).
The optional `unknown_doc_rating` parameter can be used to specify a default rating for unlabeled documents.

See Also:

Discounted Cumulative Gain

Nested Class Summary

Nested classes/interfaces inherited from interface org.elasticsearch.common.xcontent.ToXContent

org.elasticsearch.common.xcontent.ToXContent.DelegatingMapParams, org.elasticsearch.common.xcontent.ToXContent.MapParams, org.elasticsearch.common.xcontent.ToXContent.Params

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

org.elasticsearch.common.io.stream.Writeable.Reader<V extends java.lang.Object>, org.elasticsearch.common.io.stream.Writeable.Writer<V extends java.lang.Object>

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	NAME

Fields inherited from interface org.elasticsearch.common.xcontent.ToXContent

EMPTY_PARAMS

Constructor Summary

Constructors

Constructor	Description
DiscountedCumulativeGain()
DiscountedCumulativeGain(boolean normalize, java.lang.Integer unknownDocRating, int k)

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object obj)
EvalQueryQuality	evaluate(java.lang.String taskId, org.elasticsearch.search.SearchHit[] hits, java.util.List<RatedDocument> ratedDocs)	Returns a single metric representing the ranking quality of a set of returned documents wrt.
java.util.Optional<java.lang.Integer>	forcedSearchSize()	Metrics can define a size of the search hits windows they want to retrieve by overwriting this method.
static DiscountedCumulativeGain	fromXContent(org.elasticsearch.common.xcontent.XContentParser parser)
java.lang.Integer	getUnknownDocRating()	get the rating used for unrated documents
java.lang.String	getWriteableName()
int	hashCode()
org.elasticsearch.common.xcontent.XContentBuilder	toXContent(org.elasticsearch.common.xcontent.XContentBuilder builder, org.elasticsearch.common.xcontent.ToXContent.Params params)
void	writeTo(org.elasticsearch.common.io.stream.StreamOutput out)

Methods inherited from interface org.elasticsearch.index.rankeval.EvaluationMetric

combine

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.elasticsearch.common.xcontent.ToXContentObject

isFragment

Field Detail

NAME

public static final java.lang.String NAME

See Also:

Constant Field Values

Constructor Detail

DiscountedCumulativeGain

public DiscountedCumulativeGain()

DiscountedCumulativeGain

public DiscountedCumulativeGain(boolean normalize,
                                java.lang.Integer unknownDocRating,
                                int k)

Parameters:

normalize - If set to true, dcg will be normalized (ndcg) See https://en.wikipedia.org/wiki/Discounted_cumulative_gain

unknownDocRating - the rating for documents the user hasn't supplied an explicit rating for

k - the search window size all request use.

Method Detail

writeTo

public void writeTo(org.elasticsearch.common.io.stream.StreamOutput out)
             throws java.io.IOException

Specified by:

writeTo in interface org.elasticsearch.common.io.stream.Writeable

Throws:

java.io.IOException

getWriteableName

public java.lang.String getWriteableName()

Specified by:

getWriteableName in interface org.elasticsearch.common.io.stream.NamedWriteable

getUnknownDocRating

public java.lang.Integer getUnknownDocRating()

get the rating used for unrated documents

forcedSearchSize

public java.util.Optional<java.lang.Integer> forcedSearchSize()

Description copied from interface: EvaluationMetric

Metrics can define a size of the search hits windows they want to retrieve by overwriting this method. The default implementation returns an empty optional.

Specified by:

forcedSearchSize in interface EvaluationMetric

Returns:

the number of search hits this metrics requests

evaluate

public EvalQueryQuality evaluate(java.lang.String taskId,
                                 org.elasticsearch.search.SearchHit[] hits,
                                 java.util.List<RatedDocument> ratedDocs)

Description copied from interface: EvaluationMetric

Returns a single metric representing the ranking quality of a set of returned documents wrt. to a set of document ids labeled as relevant for this search.

Specified by:

evaluate in interface EvaluationMetric

Parameters:

taskId - the id of the query for which the ranking is currently evaluated

hits - the result hits as returned by a search request

ratedDocs - the documents that were ranked by human annotators for this query case

Returns:

some metric representing the quality of the result hit list wrt. to relevant doc ids.

fromXContent

public static DiscountedCumulativeGain fromXContent(org.elasticsearch.common.xcontent.XContentParser parser)

toXContent

public org.elasticsearch.common.xcontent.XContentBuilder toXContent(org.elasticsearch.common.xcontent.XContentBuilder builder,
                                                                    org.elasticsearch.common.xcontent.ToXContent.Params params)
                                                             throws java.io.IOException

Specified by:

toXContent in interface org.elasticsearch.common.xcontent.ToXContent

Throws:

java.io.IOException

equals

public final boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public final int hashCode()

Overrides:

hashCode in class java.lang.Object