Package eu.h2020.helios_social.modules.socialgraphmining.measures

Class HitRate

java.lang.Object

eu.h2020.helios_social.modules.socialgraphmining.measures.HitRate

All Implemented Interfaces:

Measure

public class HitRate
extends java.lang.Object
implements Measure

This Measure provides a HitRate@k evaluation, which measures whether the occurred interactions lie among the top k recommendations provided by SocialGraphMiner.recommendInteractions(Context). Ties are resolved towards not favoring the recommendation, so that for example all-zero recommendations are evaluated as failed ones. Since this Measure is used to assess only one prediction instance at a time, its assessment is either 0 or 1 and needs be aggregated across multiple interactions using another measure, such as Accumulate. Since it makes no sense to assess recommendations between too few nodes (e.g. less than k), the evaluateSend(SocialGraphMiner, Context, Node) method returns a NaN value if there are fewer than a preselected number of predictions.

Author:

Emmanouil Krasanakis

Constructor Summary

Constructors

Constructor	Description
HitRate()	Default constructor for calculating HitRate@3.
HitRate(int k)	Constructor that creates for calculating HitRate@k when there are at least 2k or more recommendations.
HitRate(int k, int requiredCandidates)	Constructor that creates a HitRate@k evaluation.

Method Summary

Modifier and Type	Method	Description
double	evaluateSend(SocialGraphMiner socialGraphMiner, eu.h2020.helios_social.core.contextualegonetwork.Context context, eu.h2020.helios_social.core.contextualegonetwork.Node dst)	Supervised evaluation of interactions sent by each node.

Methods inherited from interface eu.h2020.helios_social.modules.socialgraphmining.Measure

lastEvaluation

Methods inherited from class java.lang.Object

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

Constructor Detail

HitRate

public HitRate()

Default constructor for calculating HitRate@3.

See Also:

HitRate(int)

HitRate

public HitRate(int k)

Constructor that creates for calculating HitRate@k when there are at least 2k or more recommendations.

Parameters:

k - The number of top recommendations in which to check that occurring interactions reside.

See Also:

HitRate(int, int)

HitRate

public HitRate(int k,
               int requiredCandidates)

Constructor that creates a HitRate@k evaluation.

Parameters:

k - The number of top recommendations in which to check that occurring interactions reside.

requiredCandidates - The number of recommendations that need be available for the evaluation to be valid.

Method Detail

evaluateSend

public double evaluateSend(SocialGraphMiner socialGraphMiner,
                           eu.h2020.helios_social.core.contextualegonetwork.Context context,
                           eu.h2020.helios_social.core.contextualegonetwork.Node dst)

Description copied from interface: Measure

Supervised evaluation of interactions sent by each node.

Specified by:

evaluateSend in interface Measure

Parameters:

socialGraphMiner - The social graph miner used to perform the prediction.

context - The context in which new interactions are predicted.

dst - The destination node.

Returns:

The evaluation score - typically a value in the range [0,1], but NaN can be returned if the prediction cannot be assessed (e.g. due to invalid parameters of the measure).