Base class for rating predictors that use some kind of kNN. More...
Public Member Functions | |
override void | Add (int user_id, int item_id, double rating) |
override void | AddItem (int item_id) |
override void | AddUser (int user_id) |
virtual bool | CanPredict (int user_id, int item_id) |
Check whether a useful prediction can be made for a given user-item combination. | |
Object | Clone () |
create a shallow copy of the object | |
KNN () | |
Create a new KNN recommender. | |
override void | LoadModel (string filename) |
Get the model parameters from a file. | |
override double | Predict (int user_id, int item_id) |
Predict rating or score for a given user-item combination. | |
virtual void | RemoveItem (int item_id) |
override void | RemoveRating (int user_id, int item_id) |
virtual void | RemoveUser (int user_id) |
override void | SaveModel (string filename) |
Save the model parameters to a file. | |
override string | ToString () |
Return a string representation of the recommender. | |
override void | Train () |
Learn the model parameters of the recommender from the training data. | |
override void | UpdateRating (int user_id, int item_id, double rating) |
Protected Member Functions | |
override void | InitModel () |
Inits the recommender model. | |
virtual void | RetrainItem (int item_id) |
virtual void | RetrainUser (int user_id) |
Protected Attributes | |
CorrelationMatrix | correlation |
Correlation matrix over some kind of entity. | |
double | max_rating |
The max rating value. | |
double | min_rating |
The min rating value. | |
IRatings | ratings |
rating data | |
Properties | |
uint | K [get, set] |
Number of neighbors to take into account for predictions. | |
int | MaxItemID [get, set] |
Maximum item ID. | |
virtual double | MaxRating [get, set] |
The max rating value. | |
int | MaxUserID [get, set] |
Maximum user ID. | |
virtual double | MinRating [get, set] |
The min rating value. | |
virtual IRatings | Ratings [get, set] |
The rating data. | |
double | RegI [get, set] |
Regularization parameter for the item biases. | |
double | RegU [get, set] |
Regularization parameter for the user biases. | |
bool | UpdateItems [get, set] |
true if items shall be updated when doing online updates | |
bool | UpdateUsers [get, set] |
true if users shall be updated when doing online updates |
Base class for rating predictors that use some kind of kNN.
The method is described in section 2.2 of Yehuda Koren: Factor in the Neighbors: Scalable and Accurate Collaborative Filtering, Transactions on Knowledge Discovery from Data (TKDD), 2009.
This engine does NOT support online updates.
virtual bool CanPredict | ( | int | user_id, | |
int | item_id | |||
) | [virtual, inherited] |
Check whether a useful prediction can be made for a given user-item combination.
user_id | the user ID | |
item_id | the item ID |
Implements IRecommender.
Reimplemented in BiPolarSlopeOne, GlobalAverage, ItemAverage, SlopeOne, and UserAverage.
Object Clone | ( | ) | [inherited] |
create a shallow copy of the object
override void InitModel | ( | ) | [protected, virtual, inherited] |
Inits the recommender model.
This method is called by the Train() method. When overriding, please call base.InitModel() to get the functions performed in the base class.
Reimplemented from RatingPredictor.
override void LoadModel | ( | string | filename | ) | [virtual] |
Get the model parameters from a file.
filename | the name of the file to read from |
Reimplemented from UserItemBaseline.
Reimplemented in ItemKNN.
override double Predict | ( | int | user_id, | |
int | item_id | |||
) | [virtual, inherited] |
Predict rating or score for a given user-item combination.
user_id | the user ID | |
item_id | the item ID |
Implements RatingPredictor.
override void SaveModel | ( | string | filename | ) | [virtual] |
Save the model parameters to a file.
filename | the name of the file to write to |
Reimplemented from UserItemBaseline.
override string ToString | ( | ) | [inherited] |
Return a string representation of the recommender.
The ToString() method of recommenders should list the class name and all hyperparameters, separated by space characters.
Implements IRecommender.
Reimplemented in ItemAttributeKNN, ItemKNNCosine, ItemKNNPearson, UserAttributeKNN, UserKNNCosine, and UserKNNPearson.
CorrelationMatrix correlation [protected] |
Correlation matrix over some kind of entity.
double max_rating [protected, inherited] |
The max rating value.
double min_rating [protected, inherited] |
The min rating value.
uint K [get, set] |
Number of neighbors to take into account for predictions.
int MaxItemID [get, set, inherited] |
Maximum item ID.
Maximum item ID
virtual double MaxRating [get, set, inherited] |
int MaxUserID [get, set, inherited] |
Maximum user ID.
Maximum user ID
virtual double MinRating [get, set, inherited] |
double RegI [get, set, inherited] |
Regularization parameter for the item biases.
If not set, the recommender will try to find suitable values.
double RegU [get, set, inherited] |
Regularization parameter for the user biases.
If not set, the recommender will try to find suitable values.
bool UpdateItems [get, set, inherited] |
true if items shall be updated when doing online updates
true if items shall be updated when doing online updates
bool UpdateUsers [get, set, inherited] |
true if users shall be updated when doing online updates
true if users shall be updated when doing online updates