Package es.upm.etsisi.cf4j.data

Class 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 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

      • exportToCSV

        public void exportToCSV​(String path,
                        String baseName,
                        boolean useIndexesAsIds)
                 throws IOException
        Exports datamodel into a CSV for train ratings and other CSV for test ratings.
        Parameters:
        path - Path where store the files
        baseName - Base name for CSV files. Suffixes
        useIndexesAsIds - Use CF4J indexes as ids
        Throws:
        IOException - IOException

      • exportToCSV

        public void exportToCSV​(String path,
                        String baseName)
                 throws IOException
        Exports datamodel into a CSV for train ratings and other CSV for test ratings.
        Parameters:
        path - Path where store the files
        baseName - Base name for CSV files. Suffixes.
        Throws:
        IOException - IOException

      • exportToCSV

        public void exportToCSV​(String path,
                        String baseName,
                        String separator)
                 throws IOException
        Exports datamodel into a CSV for train ratings and other CSV for test ratings.
        Parameters:
        path - Path where store the files
        baseName - Base name for CSV files. Suffixes.
        separator - CSV separator
        Throws:
        IOException - IOException

      • exportToCSV

        public void exportToCSV​(String path,
                        String baseName,
                        String separator,
                        boolean useIndexesAsIds)
                 throws IOException
        Exports datamodel into a CSV for train ratings and other CSV for test ratings.
        Parameters:
        path - Path where store the files
        baseName - Base name for CSV files. Suffixes
        separator - CSV separator
        useIndexesAsIds - Use CF4J indexes as ids
        Throws:
        IOException - IOException