MyMediaLite  3.03
Public Member Functions | Protected Member Functions | Protected Attributes | Properties
Ratings Class Reference

Data structure for storing ratings. More...

Inheritance diagram for Ratings:
DataSet IRatings IDataSet IDataSet CombinedRatings RatingsProxy StaticRatings TimedRatings StaticByteRatings TimedRatingsProxy

List of all members.

Public Member Functions

virtual void Add (int user_id, int item_id, byte rating)
 Add byte-valued rating to the collection.
virtual void Add (int user_id, int item_id, float rating)
 Add float-valued rating to the collection.
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.
int GetIndex (int user_id, int item_id)
 Get index for a given user and item.
int GetIndex (int user_id, int item_id, ICollection< int > indexes)
 Get index for given user and item.
ISet< int > GetItems (IList< int > indices)
 Get all items that are referenced by a given list of indices.
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.
int IndexOf (float item)
virtual void InitScale ()
 Initialize the Scale property.
void Insert (int index, float item)
 Ratings ()
 Default constructor.
 Ratings (SerializationInfo info, StreamingContext context)
bool Remove (float item)
virtual void RemoveAt (int index)
override void RemoveItem (int item_id)
 Remove all events related to a given item.
override void RemoveUser (int user_id)
 Remove all events related to a given user.
virtual bool TryGet (int user_id, int item_id, out float rating)
 Try to retrieve a rating for a given user-item combination.
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.
bool TryGetIndex (int user_id, int item_id, out int index)
 Try to get the index for given user and item.
bool TryGetIndex (int user_id, int item_id, ICollection< int > indexes, out int index)
 Try to get the index for given user and item.

Protected Member Functions

void UpdateCountsAndIndices (ISet< int > users, ISet< int > items)
 update user- and item-wise counts and indices

Protected Attributes

IList< IList< int > > by_item
 Indices organized by item.
IList< IList< int > > by_user
 Indices organized by user.
IList< int > count_by_item
 field for storing the count per item
IList< int > count_by_user
 field for storing the count per user
IList< float > Values

Properties

IList< int > AllItems [get]
 all item IDs in the dataset
IList< int > AllUsers [get]
 all user IDs in the dataset
float Average [get]
 average rating in the dataset
IList< IList< int > > ByItem [get]
 indices by item
IList< IList< int > > ByUser [get]
 indices by user
new int Count [get]
 the number of interaction events in the dataset
virtual int Count [get]
 the number of interaction events in the dataset
IList< int > CountByItem [get]
 count by item
IList< int > CountByUser [get]
 count by user
bool IsReadOnly [get]
IList< int > Items [get, set]
 the item entries
int MaxItemID [get, set]
 the maximum item ID in the dataset
int MaxUserID [get, set]
 the maximum user ID in the dataset
IList< int > RandomIndex [get]
 get a randomly ordered list of all indices
RatingScale Scale [get, set]
 information about the scale of the ratings in the dataset
virtual float this[int index] [get, set]
virtual float this[int user_id, int item_id] [get]
 Directly access rating by user and item.
IList< int > Users [get, set]
 the user entries

Detailed Description

Data structure for storing ratings.

Small memory overhead for added flexibility.

This data structure supports incremental updates.


Constructor & Destructor Documentation

Ratings ( ) [inline]

Default constructor.


Member Function Documentation

virtual void Add ( int  user_id,
int  item_id,
byte  rating 
) [inline, virtual]

Add byte-valued rating to the collection.

Parameters:
user_idthe user ID
item_idthe item ID
ratingthe rating

Implements IRatings.

Reimplemented in StaticByteRatings.

virtual void Add ( int  user_id,
int  item_id,
float  rating 
) [inline, virtual]

Add float-valued rating to the collection.

Parameters:
user_idthe user ID
item_idthe item ID
ratingthe rating

Implements IRatings.

Reimplemented in StaticByteRatings, StaticRatings, and TimedRatings.

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

Directly access rating by user and item.

Parameters:
user_idthe user ID
item_idthe item ID
indexesthe 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 
) [inline, inherited]

Get index for a given user and item.

Parameters:
user_idthe user ID
item_idthe 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 
) [inline, inherited]

Get index for given user and item.

Parameters:
user_idthe user ID
item_idthe item ID
indexesthe 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) [inline, inherited]

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

Parameters:
indicesthe indices to take into account
Returns:
all items referenced by the list of indices

Implements IDataSet.

ISet<int> GetUsers ( IList< int >  indices) [inline, inherited]

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

Parameters:
indicesthe indices to take into account
Returns:
all users referenced by the list of indices

Implements IDataSet.

virtual void InitScale ( ) [inline, virtual]

Initialize the Scale property.

Implements IRatings.

Reimplemented in StaticByteRatings.

override void RemoveItem ( int  item_id) [inline, virtual]

Remove all events related to a given item.

Parameters:
item_idthe item ID

Implements DataSet.

Reimplemented in StaticRatings, and RatingsProxy.

override void RemoveUser ( int  user_id) [inline, virtual]

Remove all events related to a given user.

Parameters:
user_idthe user ID

Implements DataSet.

Reimplemented in StaticRatings, and RatingsProxy.

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

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

Parameters:
user_idthe user ID
item_idthe item ID
ratingwill 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 
) [inline, virtual]

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

Parameters:
user_idthe user ID
item_idthe item ID
indexesthe indexes to look at
ratingwill 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 
) [inline, inherited]

Try to get the index for given user and item.

Parameters:
user_idthe user ID
item_idthe item ID
indexwill 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 
) [inline, inherited]

Try to get the index for given user and item.

Parameters:
user_idthe user ID
item_idthe item ID
indexesthe indexes to look at
indexwill 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 
) [inline, protected]

update user- and item-wise counts and indices

Parameters:
usersthe modified users
itemsthe modified itemsItems.

Member Data Documentation

IList<IList<int> > by_item [protected, inherited]

Indices organized by item.

IList<IList<int> > by_user [protected, inherited]

Indices organized by user.

IList<int> count_by_item [protected, inherited]

field for storing the count per item

IList<int> count_by_user [protected, inherited]

field for storing the count per user


Property Documentation

IList<int> AllItems [get, inherited]

all item IDs in the dataset

Implements IDataSet.

IList<int> AllUsers [get, inherited]

all user IDs in the dataset

Implements IDataSet.

float Average [get]

average rating in the dataset

Implements IRatings.

IList<IList<int> > ByItem [get, inherited]

indices by item

Should be implemented as a lazy data structure

Implements IDataSet.

IList<IList<int> > ByUser [get, inherited]

indices by user

Should be implemented as a lazy data structure

Implements IDataSet.

new int Count [get, inherited]

the number of interaction events in the dataset

Implements IDataSet.

Implemented in StaticRatings.

virtual int Count [get, inherited]

the number of interaction events in the dataset

Implements IDataSet.

Reimplemented in StaticRatings.

IList<int> CountByItem [get, inherited]

count by item

Should be implemented as a lazy data structure

Implements IDataSet.

IList<int> CountByUser [get, inherited]

count by user

Should be implemented as a lazy data structure

Implements IDataSet.

IList<int> Items [get, set, inherited]

the item entries

Implements IDataSet.

int MaxItemID [get, set, inherited]

the maximum item ID in the dataset

Implements IDataSet.

int MaxUserID [get, set, inherited]

the maximum user ID in the dataset

Implements IDataSet.

IList<int> RandomIndex [get, inherited]

get a randomly ordered list of all indices

Should be implemented as a lazy data structure

Implements IDataSet.

RatingScale Scale [get, set]

information about the scale of the ratings in the dataset

Implements IRatings.

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

Directly access rating by user and item.

Parameters:
user_idthe user ID
item_idthe item ID

the rating value for the given user and item

Implements IRatings.

Reimplemented in StaticByteRatings.

IList<int> Users [get, set, inherited]

the user entries

Implements IDataSet.


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