DataModel (CF4J 2.1.0 API Documentation)

java.lang.Object
- es.upm.etsisi.cf4j.data.DataModel

All Implemented Interfaces:

Serializable
```
public class DataModel
extends Object
implements Serializable
```
This class manages all the information related with a collaborative filtering based recommender system. A DataModel should be instantiated from a DataSet. This class also provides the possibility to manage serialized files based on instances of this class.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description

DataModel(DataSet dataset)
This constructor initializes the DataModel with the contents of the given DataSet.

Constructors
Constructor and Description
`DataModel(DataSet dataset)` This constructor initializes the DataModel with the contents of the given DataSet.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addRating(int userIndex, int itemIndex, double rating)` Adds a single (training) rating to the DataModel.
`void`	`addTestRating(int testUserIndex, int testItemIndex, double rating)` Adds a single test rating to the DataModel.
`int`	`findItemIndex(String itemId)` Finds the itemIndex of an Item at the Items' array given its unique id.
`int`	`findTestItemIndex(String itemId)` Finds the testItemIndex of a TestItem at the TestItem' array given its unique id.
`int`	`findTestUserIndex(String userId)` Finds the testUserIndex of a TestUser at the TestUsers' array given his/her unique id.
`int`	`findUserIndex(String userId)` Finds the userIndex of a User at the Users' array given his/her unique id.
`DataBank`	`getDataBank()` Gets the DataBank instance that stores heterogeneous information related to the DataModel.
`Item`	`getItem(int itemIndex)` Gets an Item by its index.
`Item[]`	`getItems()` Gets the array of Items.
`double`	`getMaxRating()` Gets the maximum (training) rating.
`double`	`getMaxTestRating()` Gets the maximum test rating.
`double`	`getMinRating()` Gets the minimum (training) rating.
`double`	`getMinTestRating()` Gets the minimum test rating.
`int`	`getNumberOfItems()` Gets the number of items contained in the DataModel.
`int`	`getNumberOfRatings()` Return the number of ratings contained in the DataModel.
`int`	`getNumberOfTestItems()` Gets the number of test items contained in the DataModel.
`int`	`getNumberOfTestRatings()` Return the number of test ratings contained in the DataModel.
`int`	`getNumberOfTestUsers()` Gets the number of test users contained in the DataModel.
`int`	`getNumberOfUsers()` Gets the number of users contained in the DataModel.
`double`	`getRatingAverage()` Gets the average of (training) ratings.
`TestItem`	`getTestItem(int testItemIndex)` Gets a TestItem by its index.
`TestItem[]`	`getTestItems()` Gets the array of TestItems.
`double`	`getTestRatingAverage()` Gets the average of test ratings.
`TestUser`	`getTestUser(int testUserIndex)` Gets a TestUser by his/her test index.
`TestUser[]`	`getTestUsers()` Gets the array of TestUsers.
`User`	`getUser(int userIndex)` Gets an User by his/her index.
`User[]`	`getUsers()` Gets the array of Users.
`static DataModel`	`load(String filePath)` Loads a DataModel from a previously serialized file (see save() method).
`void`	`save(String filePath)` Saves the content of the DataModel in a serialized file.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - DataModel
```
public DataModel(DataSet dataset)
```
    This constructor initializes the DataModel with the contents of the given DataSet. Data contained in the DataSet is stored in 4 different arrays: user, testUser, item and testItems. Keeping the main behaviour of the collaborative filtering in mind, any TestUser could have voted both Item or TestItem. In the same way, any testItem could have been voted by a User and TestUser. In the other hand, Users and Items will not have a test part.
    
    Parameters:
    
    dataset - DataSet to be added to the DataModel.
- Method Detail
  - save
```
public void save(String filePath)
          throws IOException
```
    Saves the content of the DataModel in a serialized file.
    
    Parameters:
    
    filePath - Path where the file will be stored, filename and extension should be included in the path.
    
    Throws:
    
    IOException - When the file is not accessible by the system with write permissions.
  - load
```
public static DataModel load(String filePath)
                      throws IOException,
                             ClassNotFoundException
```
    Loads a DataModel from a previously serialized file (see save() method).
    
    Parameters:
    
    filePath - Path where the file will be loaded, filename and extension should be included in the path.
    
    Returns:
    
    If te file was successfully loaded, this method returns the DataModel.
    
    Throws:
    
    IOException - When the file is not accessible by the system with reading permissions.
    
    ClassNotFoundException - When the file exist and is accessible, but it doesn't contains a valid instance.
  - addTestRating
```
public void addTestRating(int testUserIndex,
                          int testItemIndex,
                          double rating)
```
    Adds a single test rating to the DataModel.
    
    Parameters:
    
    testUserIndex - Index of the TestUser at the DataModel
    
    testItemIndex - Index of the TestItem at the DataModel
    
    rating - Rating value
  - addRating
```
public void addRating(int userIndex,
                      int itemIndex,
                      double rating)
```
    Adds a single (training) rating to the DataModel.
    
    Parameters:
    
    userIndex - Index of the User at the DataModel
    
    itemIndex - Index of the Item at the DataModel
    
    rating - Rating value
  - getUsers
```
public User[] getUsers()
```
    Gets the array of Users. If you need a specific User it is recommended to use the getUser() method.
    
    Returns:
    
    Array of Users
  - getTestUsers
```
public TestUser[] getTestUsers()
```
    Gets the array of TestUsers. If you need a specific TestUser it is recommended to use the getTestUser() method.
    
    Returns:
    
    Array of TestUsers
  - getItems
```
public Item[] getItems()
```
    Gets the array of Items. If you need a specific Item it is recommended to use the getItem() method.
    
    Returns:
    
    Array of Items
  - getTestItems
```
public TestItem[] getTestItems()
```
    Gets the array of TestItems. If you need a specific TestItem it is recommended to use the getTestItem() method.
    
    Returns:
    
    Array of TestItems
  - getDataBank
```
public DataBank getDataBank()
```
    Gets the DataBank instance that stores heterogeneous information related to the DataModel.
    
    Returns:
    
    DataBank instance
  - getNumberOfUsers
```
public int getNumberOfUsers()
```
    Gets the number of users contained in the DataModel.
    
    Returns:
    
    Number of users
  - getUser
```
public User getUser(int userIndex)
```
    Gets an User by his/her index.
    
    Parameters:
    
    userIndex - Index of the User in the Users' array inside the DataModel.
    
    Returns:
    
    User located at given userIndex
  - findUserIndex
```
public int findUserIndex(String userId)
```
    Finds the userIndex of a User at the Users' array given his/her unique id.
    
    Parameters:
    
    userId - User id to be searched.
    
    Returns:
    
    userIndex if the User exists or -1 if doesn't.
  - getNumberOfTestUsers
```
public int getNumberOfTestUsers()
```
    Gets the number of test users contained in the DataModel.
    
    Returns:
    
    Number of test users
  - getTestUser
```
public TestUser getTestUser(int testUserIndex)
```
    Gets a TestUser by his/her test index.
    
    Parameters:
    
    testUserIndex - Index of the TestUser in the TestUsers' array inside the DataModel.
    
    Returns:
    
    TestUser located at given testUserIndex
  - findTestUserIndex
```
public int findTestUserIndex(String userId)
```
    Finds the testUserIndex of a TestUser at the TestUsers' array given his/her unique id.
    
    Parameters:
    
    userId - User id to be searched.
    
    Returns:
    
    testUserIndex if the TestUser exists or -1 if doesn't.
  - getNumberOfItems
```
public int getNumberOfItems()
```
    Gets the number of items contained in the DataModel.
    
    Returns:
    
    Number of items
  - getItem
```
public Item getItem(int itemIndex)
```
    Gets an Item by its index.
    
    Parameters:
    
    itemIndex - Index of the Item in the Items' array inside the DataModel.
    
    Returns:
    
    Item located at given itemIndex
  - findItemIndex
```
public int findItemIndex(String itemId)
```
    Finds the itemIndex of an Item at the Items' array given its unique id.
    
    Parameters:
    
    itemId - Item id to be searched.
    
    Returns:
    
    itemIndex if the Item exists or -1 if doesn't.
  - getNumberOfTestItems
```
public int getNumberOfTestItems()
```
    Gets the number of test items contained in the DataModel.
    
    Returns:
    
    Number of test items
  - getTestItem
```
public TestItem getTestItem(int testItemIndex)
```
    Gets a TestItem by its index.
    
    Parameters:
    
    testItemIndex - Index of the TestItem in the TestItem' array inside the DataModel.
    
    Returns:
    
    TestItem located at given testItemIndex
  - findTestItemIndex
```
public int findTestItemIndex(String itemId)
```
    Finds the testItemIndex of a TestItem at the TestItem' array given its unique id.
    
    Parameters:
    
    itemId - Item id to be searched.
    
    Returns:
    
    testItemIndex if the TestItem exists or -1 if doesn't.
  - getMinRating
```
public double getMinRating()
```
    Gets the minimum (training) rating.
    
    Returns:
    
    Minimum rating
  - getMaxRating
```
public double getMaxRating()
```
    Gets the maximum (training) rating.
    
    Returns:
    
    Maximum rating
  - getRatingAverage
```
public double getRatingAverage()
```
    Gets the average of (training) ratings.
    
    Returns:
    
    Rating average value
  - getMinTestRating
```
public double getMinTestRating()
```
    Gets the minimum test rating.
    
    Returns:
    
    Minimum test rating
  - getMaxTestRating
```
public double getMaxTestRating()
```
    Gets the maximum test rating.
    
    Returns:
    
    Maximum test rating
  - getTestRatingAverage
```
public double getTestRatingAverage()
```
    Gets the average of test ratings.
    
    Returns:
    
    Test rating average value
  - getNumberOfRatings
```
public int getNumberOfRatings()
```
    Return the number of ratings contained in the DataModel.
    
    Returns:
    
    Number of ratings
  - getNumberOfTestRatings
```
public int getNumberOfTestRatings()
```
    Return the number of test ratings contained in the DataModel.
    
    Returns:
    
    Number of test ratings
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class DataModel

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DataModel

Method Detail

save

load

addTestRating

addRating

getUsers

getTestUsers

getItems

getTestItems

getDataBank

getNumberOfUsers

getUser

findUserIndex

getNumberOfTestUsers

getTestUser

findTestUserIndex

getNumberOfItems

getItem

findItemIndex

getNumberOfTestItems

getTestItem

findTestItemIndex

getMinRating

getMaxRating

getRatingAverage

getMinTestRating

getMaxTestRating

getTestRatingAverage

getNumberOfRatings

getNumberOfTestRatings

toString