Data structure for storing ratings with time information More...

Inheritance diagram for TimedRatings:

Public Member Functions
override void	Add (int user_id, int item_id, float rating)
	Add float-valued rating to the collection More...

virtual void	Add (int user_id, int item_id, float rating, DateTime time)
	add a rating event including time information More...

virtual void	Add (int user_id, int item_id, byte rating)
	Add byte-valued rating to the collection More...

void	Add (float item)

void	Clear ()

bool	Contains (float item)

void	CopyTo (float[] array, int index)

virtual float	Get (int user_id, int item_id, ICollection< int > indexes)
	Directly access rating by user and item More...

int	GetIndex (int user_id, int item_id)
	Get index for a given user and item More...

int	GetIndex (int user_id, int item_id, ICollection< int > indexes)
	Get index for given user and item More...

ISet< int >	GetItems (IList< int > indices)
	Get all items that are referenced by a given list of indices More...

override void	GetObjectData (SerializationInfo info, StreamingContext context)

ISet< int >	GetUsers (IList< int > indices)
	Get all users that are referenced by a given list of indices More...

int	IndexOf (float item)

virtual void	InitScale ()
	Initialize the Scale property More...

void	Insert (int index, float item)

bool	Remove (float item)

virtual void	RemoveAt (int index)

override void	RemoveItem (int item_id)
	Remove all events related to a given item More...

override void	RemoveUser (int user_id)
	Remove all events related to a given user More...

	TimedRatings ()
	Default constructor More...

	TimedRatings (SerializationInfo info, StreamingContext context)

virtual bool	TryGet (int user_id, int item_id, out float rating)
	Try to retrieve a rating for a given user-item combination More...

virtual bool	TryGet (int user_id, int item_id, ICollection< int > indexes, out float rating)
	Try to retrieve a rating for a given user-item combination More...

bool	TryGetIndex (int user_id, int item_id, out int index)
	Try to get the index for given user and item More...

bool	TryGetIndex (int user_id, int item_id, ICollection< int > indexes, out int index)
	Try to get the index for given user and item More...

Protected Member Functions
void	UpdateCountsAndIndices (ISet< int > users, ISet< int > items)
	update user- and item-wise counts and indices More...

Protected Attributes
IList< IList< int > >	by_item
	Indices organized by item More...

IList< IList< int > >	by_user
	Indices organized by user More...

IList< int >	count_by_item
	field for storing the count per item More...

IList< int >	count_by_user
	field for storing the count per user More...

IList< float >	Values

Properties
IList< int >	AllItems `[get]`

IList< int >	AllUsers `[get]`

float	Average `[get]`

IList< IList< int > >	ByItem `[get]`

IList< IList< int > >	ByUser `[get]`

new int	Count `[get]`

virtual int	Count `[get]`

IList< int >	CountByItem `[get]`

IList< int >	CountByUser `[get]`

DateTime	EarliestTime `[get, protected set]`

bool	IsReadOnly `[get]`

IList< int >	Items `[get, protected set]`

DateTime	LatestTime `[get, protected set]`

int	MaxItemID `[get, protected set]`

int	MaxUserID `[get, protected set]`

IList< int >	RandomIndex `[get]`

RatingScale	Scale `[get, protected set]`

virtual float	this[int index] `[get, set]`

virtual float	this[int user_id, int item_id] `[get]`

IList< DateTime >	Times `[get, protected set]`

IList< int >	Users `[get, protected set]`

Detailed Description

Data structure for storing ratings with time information

This data structure supports incremental updates.

Loading the Netflix Prize data set (100,000,000 ratings) into this data structure requires about 3.2 GB of memory.

Constructor & Destructor Documentation

TimedRatings ( )

inline

Default constructor

Member Function Documentation

override void Add	(	int	user_id,
		int	item_id,
		float	rating
	)

inlinevirtual

Add float-valued rating to the collection

Parameters

user_id	the user ID
item_id	the item ID
rating	the rating

Reimplemented from Ratings.

virtual void Add	(	int	user_id,
		int	item_id,
		float	rating,
		DateTime	time
	)

inlinevirtual

add a rating event including time information

It is up to the user of a class implementing this interface to decide whether the DateTime object represent local time, UTC, or any other time.

Parameters

user_id	the user ID
item_id	the item ID
rating	the rating value
time	A DateTime specifying the time of the rating event

Implements ITimedRatings.

virtual void Add	(	int	user_id,
		int	item_id,
		byte	rating
	)

inlinevirtualinherited

Add byte-valued rating to the collection

Parameters

user_id	the user ID
item_id	the item ID
rating	the rating

Implements IRatings.

Reimplemented in StaticByteRatings.

virtual float Get	(	int	user_id,
		int	item_id,
		ICollection< int >	indexes
	)

inlinevirtualinherited

Directly access rating by user and item

Parameters

user_id	the user ID
item_id	the item ID
indexes	the indexes to look at

Returns: the first rating encountered that matches the user ID and item ID

Implements IRatings.

Reimplemented in StaticByteRatings.

int GetIndex	(	int	user_id,
		int	item_id
	)

inlineinherited

Get index for a given user and item

Parameters

user_id	the user ID
item_id	the item ID

Returns: the index of the first event encountered that matches the user ID and item ID

Implements IDataSet.

int GetIndex	(	int	user_id,
		int	item_id,
		ICollection< int >	indexes
	)

inlineinherited

Get index for given user and item

Parameters

user_id	the user ID
item_id	the item ID
indexes	the indexes to look at

Returns: the index of the first event encountered that matches the user ID and item ID

Implements IDataSet.

ISet<int> GetItems ( IList< int > indices )

inlineinherited

Get all items that are referenced by a given list of indices

Parameters

indices the indices to take into account

Returns: all items referenced by the list of indices

Implements IDataSet.

ISet<int> GetUsers ( IList< int > indices )

inlineinherited

Get all users that are referenced by a given list of indices

Parameters

indices the indices to take into account

Returns: all users referenced by the list of indices

Implements IDataSet.

virtual void InitScale ( )

inlinevirtualinherited

Initialize the Scale property

Implements IRatings.

Reimplemented in StaticByteRatings.

override void RemoveItem ( int item_id )

inlinevirtualinherited

Remove all events related to a given item

Parameters

item_id the item ID

Implements DataSet.

Reimplemented in StaticRatings, and RatingsProxy.

override void RemoveUser ( int user_id )

inlinevirtualinherited

Remove all events related to a given user

Parameters

user_id the user ID

Implements DataSet.

Reimplemented in StaticRatings, and RatingsProxy.

virtual bool TryGet	(	int	user_id,
		int	item_id,
		out float	rating
	)

inlinevirtualinherited

Try to retrieve a rating for a given user-item combination

Parameters

user_id	the user ID
item_id	the item ID
rating	will contain the first rating encountered that matches the user ID and item ID

Returns: true if a rating was found for the user and item

Implements IRatings.

Reimplemented in StaticByteRatings.

virtual bool TryGet	(	int	user_id,
		int	item_id,
		ICollection< int >	indexes,
		out float	rating
	)

inlinevirtualinherited

Try to retrieve a rating for a given user-item combination

Parameters

user_id	the user ID
item_id	the item ID
indexes	the indexes to look at
rating	will contain the first rating encountered that matches the user ID and item ID

Returns: true if a rating was found for the user and item

Implements IRatings.

Reimplemented in StaticByteRatings.

bool TryGetIndex	(	int	user_id,
		int	item_id,
		out int	index
	)

inlineinherited

Try to get the index for given user and item

Parameters

user_id	the user ID
item_id	the item ID
index	will contain the index of the first event encountered that matches the user ID and item ID

Returns: true if an index was found for the user and item

Implements IDataSet.

bool TryGetIndex	(	int	user_id,
		int	item_id,
		ICollection< int >	indexes,
		out int	index
	)

inlineinherited

Try to get the index for given user and item

Parameters

user_id	the user ID
item_id	the item ID
indexes	the indexes to look at
index	will contain the index of the first event encountered that matches the user ID and item ID

Returns: true if an index was found for the user and item

Implements IDataSet.

void UpdateCountsAndIndices	(	ISet< int >	users,
		ISet< int >	items
	)

inlineprotectedinherited

update user- and item-wise counts and indices

Parameters

users	the modified users
items	the modified itemsItems.

Member Data Documentation

IList<IList<int> > by_item

protectedinherited

Indices organized by item

IList<IList<int> > by_user

protectedinherited

Indices organized by user

IList<int> count_by_item

protectedinherited

field for storing the count per item

IList<int> count_by_user

protectedinherited

field for storing the count per user

The documentation for this class was generated from the following file:

TimedRatings.cs

Public Member Functions

Protected Member Functions

Protected Attributes

Properties

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation