org.grouplens.lenskit.data.history

Class EventCountUserHistorySummarizer

java.lang.Object

org.grouplens.lenskit.data.history.EventCountUserHistorySummarizer

All Implemented Interfaces:

UserHistorySummarizer

@Shareable
public final class EventCountUserHistorySummarizer
extends Object
implements UserHistorySummarizer

Summarize a history by counting all events referencing an item. The history can be filtered by type prior to counting.

Field Summary

Fields

Modifier and Type	Field and Description
protected Class<? extends Event>	wantedType

Constructor Summary

Constructors

Constructor and Description
EventCountUserHistorySummarizer() Create a summarizer that counts all events.
EventCountUserHistorySummarizer(Class<? extends Event> type) Create a summarizer that counts events of a particular type.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Class<? extends Event>	eventTypeWanted() Get the supertype of all events required by this summarizer.
int	hashCode()
SparseVector	summarize(UserHistory<? extends Event> history) Compute a vector summary of a user's history.

Methods inherited from class java.lang.Object

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

Field Detail

wantedType

protected final Class<? extends Event> wantedType

Constructor Detail

EventCountUserHistorySummarizer

public EventCountUserHistorySummarizer()

Create a summarizer that counts all events.

EventCountUserHistorySummarizer

@Inject
public EventCountUserHistorySummarizer(@EventType @Nonnull
                                               Class<? extends Event> type)

Create a summarizer that counts events of a particular type.

Parameters:

type - The type of event to count.

Method Detail

eventTypeWanted

public Class<? extends Event> eventTypeWanted()

Description copied from interface: UserHistorySummarizer

Get the supertype of all events required by this summarizer.

Specified by:

eventTypeWanted in interface UserHistorySummarizer

Returns:

A type such that any type used by this summarizer is a subtype of it.

summarize

@Nonnull
public SparseVector summarize(@Nonnull
                                       UserHistory<? extends Event> history)

Description copied from interface: UserHistorySummarizer

Compute a vector summary of a user's history.

Specified by:

summarize in interface UserHistorySummarizer

Parameters:

history - The history to summarize.

Returns:

A vector summarizing the user's history.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object