prea.recommender.baseline
Class Average

java.lang.Object
  extended by prea.recommender.baseline.BaselineRecommender
      extended by prea.recommender.baseline.Average
All Implemented Interfaces:
Recommender

public class Average
extends BaselineRecommender

The class implementing a baseline, predicting by overall average of training set ratings.

Since:
2012. 4. 20
Version:
1.1
Author:
Joonseok Lee

Field Summary
private  double constantValue
          The value which will be used for predicting all ratings.
 
Fields inherited from class prea.recommender.baseline.BaselineRecommender
itemCount, maxValue, minValue, rateMatrix, userCount
 
Constructor Summary
Average(int uc, int ic, double max, double min)
          Construct a constant model with the given data.
 
Method Summary
 void buildModel(SparseMatrix rm)
          Build a model with given training set.
 double predict(int userId, int itemId)
          Predict a rating for the given user and item.
 
Methods inherited from class prea.recommender.baseline.BaselineRecommender
evaluate
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

constantValue

private double constantValue
The value which will be used for predicting all ratings.

Constructor Detail

Average

public Average(int uc,
               int ic,
               double max,
               double min)
Construct a constant model with the given data.

Parameters:
uc - The number of users in the dataset.
ic - The number of items in the dataset.
max - The maximum rating value in the dataset.
min - The minimum rating value in the dataset.
Method Detail

buildModel

public void buildModel(SparseMatrix rm)
Build a model with given training set.

Specified by:
buildModel in interface Recommender
Overrides:
buildModel in class BaselineRecommender
Parameters:
rm - Training data set.

predict

public double predict(int userId,
                      int itemId)
Predict a rating for the given user and item.

Specified by:
predict in class BaselineRecommender
Parameters:
userId - The target user.
itemId - The target item.
Returns:
predicted rating.