org.grouplens.lenskit.data.pref

Interface Preference

All Known Subinterfaces:

IndexedPreference

All Known Implementing Classes:

AbstractPreference

public interface Preference

A real-valued preference a user has for an item. Preferences can be articulated by the user in the form of ratings, or they may be predicted or otherwise computed. The distinction will generally be apparent from context.

Instances of this class are immutable. All exceptions to this rule must be clearly documented, and only arise in limited contexts such as fast iteration.

Preferences are equal iff they have the same user ID, item ID, and value. The hash code of a preference is computed by passing those three values, in order, to HashCodeBuilder with default parameters.

Compatibility

Public

Method Summary

Modifier and Type	Method and Description
long	getItemId() Get the ID of the item the preference is for.
long	getUserId() Get the ID of the user whose preference this is.
double	getValue() Get the preference value.

Method Detail

getUserId

long getUserId()

Get the ID of the user whose preference this is.

Returns:

The user ID.

getItemId

long getItemId()

Get the ID of the item the preference is for.

Returns:

The item ID.

getValue

double getValue()

Get the preference value.

Returns:

The preference value.