netflix.algorithms.modelbased.reader
Class DataReaderFromMem

java.lang.Object
  netflix.algorithms.modelbased.reader.DataReaderFromMem

All Implemented Interfaces:

DataReader

public class DataReaderFromMem
extends java.lang.Object
implements DataReader

A DataReader that reads in movies data from a serialized object

Constructor Summary

DataReaderFromMem(MemHelper memHelper)

Method Summary

void	close() Closes and does necessary clean-up
double	getAverageMovieRating(int mid) Gets the average rating for a particular movie
double	getAverageRatingForUser(int uid) Gets the average rating for a user
java.util.ArrayList<Triple>	getCommonMovieRatAndAve(int uid1, int uid2) Gets all the common movie ratings and average ratings for two users
java.util.ArrayList<Pair>	getCommonMovieRatings(int uid1, int uid2) Gets the ratings for common movies for two users
java.util.ArrayList<Triple>	getCommonUserRatAndAve(int mId1, int mId2) Gets the individual and average ratings for common users between two movies
java.util.ArrayList<Pair>	getCommonUserRatings(int mId1, int mId2) Gets the ratings for common users between two movies
int	getNumberOfMovies() Returns the number of movies
int	getNumberOfUsers() Returns the number of users
int	getRating(int uid, int mid) Get the rating for a user - movie pair
int	getRatingFromComposite(int composite) Gets the rating from a user-rating or movie-rating block (see movie MemHelper for more information)

Methods inherited from class java.lang.Object

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

Constructor Detail

DataReaderFromMem

public DataReaderFromMem(MemHelper memHelper)

Method Detail

getNumberOfUsers

public int getNumberOfUsers()

Description copied from interface: DataReader

Returns the number of users

Specified by:

getNumberOfUsers in interface DataReader

Returns:

the number of users

getNumberOfMovies

public int getNumberOfMovies()

Description copied from interface: DataReader

Returns the number of movies

Specified by:

getNumberOfMovies in interface DataReader

Returns:

the number of movies

getRating

public int getRating(int uid,
                     int mid)

Description copied from interface: DataReader

Get the rating for a user - movie pair

Specified by:

getRating in interface DataReader

Parameters:

uid - User id

mid - Movie id

Returns:

rating for uid, mid

getCommonUserRatings

public java.util.ArrayList<Pair> getCommonUserRatings(int mId1,
                                                      int mId2)

Description copied from interface: DataReader

Gets the ratings for common users between two movies

Specified by:

getCommonUserRatings in interface DataReader

Returns:

getCommonUserRatAndAve

public java.util.ArrayList<Triple> getCommonUserRatAndAve(int mId1,
                                                          int mId2)

Description copied from interface: DataReader

Gets the individual and average ratings for common users between two movies

Specified by:

getCommonUserRatAndAve in interface DataReader

Returns:

getRatingFromComposite

public int getRatingFromComposite(int composite)

Description copied from interface: DataReader

Gets the rating from a user-rating or movie-rating block (see movie MemHelper for more information)

Specified by:

getRatingFromComposite in interface DataReader

Returns:

getAverageMovieRating

public double getAverageMovieRating(int mid)

Description copied from interface: DataReader

Gets the average rating for a particular movie

Specified by:

getAverageMovieRating in interface DataReader

Returns:

close

public void close()

Description copied from interface: DataReader

Closes and does necessary clean-up

Specified by:

close in interface DataReader

getCommonMovieRatings

public java.util.ArrayList<Pair> getCommonMovieRatings(int uid1,
                                                       int uid2)

Description copied from interface: DataReader

Gets the ratings for common movies for two users

Specified by:

getCommonMovieRatings in interface DataReader

Parameters:

uid1 - - id of one of the users

uid2 - - the other user's id

Returns:

- list with the ratings in the form

getAverageRatingForUser

public double getAverageRatingForUser(int uid)

Description copied from interface: DataReader

Gets the average rating for a user

Specified by:

getAverageRatingForUser in interface DataReader

Parameters:

uid - - the id of the user

Returns:

- the user's average rating

getCommonMovieRatAndAve

public java.util.ArrayList<Triple> getCommonMovieRatAndAve(int uid1,
                                                           int uid2)

Description copied from interface: DataReader

Gets all the common movie ratings and average ratings for two users

Specified by:

getCommonMovieRatAndAve in interface DataReader

Parameters:

uid1 - - id of one of the users

uid2 - - id of the other user

Returns:

- list where each entry is