org.apache.mahout.cf.taste.recommender

Interface Rescorer<T>

All Known Implementing Classes:

NullRescorer

public interface Rescorer<T>

A Rescorer simply assigns a new "score" to a thing like an ID of an item or user which a Recommender is considering returning as a top recommendation. It may be used to arbitrarily re-rank the results according to application-specific logic before returning recommendations. For example, an application may want to boost the score of items in a certain category just for one request.

A Rescorer can also exclude a thing from consideration entirely by returning true from isFiltered(Object).

Method Summary

Modifier and Type	Method and Description
boolean	isFiltered(T thing) Returns true to exclude the given thing.
double	rescore(T thing, double originalScore)

Method Detail

rescore

double rescore(T thing,
               double originalScore)

Parameters:

thing - thing to rescore

originalScore - original score

Returns:

modified score, or Double.NaN to indicate that this should be excluded entirely

isFiltered

boolean isFiltered(T thing)

Returns true to exclude the given thing.

Parameters:

thing - the thing to filter

Returns:

true to exclude, false otherwise