org.mymedialite.util
Class Utils

java.lang.Object
  extended by org.mymedialite.util.Utils

public class Utils
extends java.lang.Object

Class containing utility functions.


Method Summary
static
<T extends java.lang.Number>
double
average(java.util.Collection<T> values)
           
static java.lang.String combine(java.lang.String directory, java.lang.String filename)
           
static void displayAttributeStats(SparseBooleanMatrix user_attributes, SparseBooleanMatrix item_attributes)
          Display statistics for user and item attributes.
static void displayDataStats(IPosOnlyFeedback training_data, IPosOnlyFeedback test_data, SparseBooleanMatrix user_attributes, SparseBooleanMatrix item_attributes)
          Display data statistics for item recommendation datasets.
static void displayDataStats(IRatings train, IRatings test, SparseBooleanMatrix user_attributes, SparseBooleanMatrix item_attributes, boolean display_overlap)
          Display dataset statistics.
static
<T> java.util.Collection<T>
intersect(java.util.Collection<T> a, java.util.Collection<T> b)
           
static java.lang.Integer parseInteger(java.lang.String string)
           
static void shuffle(java.util.List<java.lang.Object> list)
          Shuffle a list in-place.
static
<T> java.util.Collection<T>
union(java.util.Collection<T> a, java.util.Collection<T> b)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

shuffle

public static void shuffle(java.util.List<java.lang.Object> list)
Shuffle a list in-place. Fisher-Yates shuffle, see http://en.wikipedia.org/wiki/Fisher–Yates_shuffle


displayDataStats

public static void displayDataStats(IRatings train,
                                    IRatings test,
                                    SparseBooleanMatrix user_attributes,
                                    SparseBooleanMatrix item_attributes,
                                    boolean display_overlap)
Display dataset statistics.

Parameters:
train - the training data
test - the test data
user_attributes - the user attributes
item_attributes - the item attributes
display_overlap - if set true, display the user/item overlap between train and test

displayDataStats

public static void displayDataStats(IPosOnlyFeedback training_data,
                                    IPosOnlyFeedback test_data,
                                    SparseBooleanMatrix user_attributes,
                                    SparseBooleanMatrix item_attributes)
Display data statistics for item recommendation datasets.

Parameters:
training_data - the training dataset
test_data - the test dataset
user_attributes - the user attributes
item_attributes - the item attributes

displayAttributeStats

public static void displayAttributeStats(SparseBooleanMatrix user_attributes,
                                         SparseBooleanMatrix item_attributes)
Display statistics for user and item attributes.

Parameters:
user_attributes - the user attributes
item_attributes - the item attributes

combine

public static java.lang.String combine(java.lang.String directory,
                                       java.lang.String filename)

average

public static <T extends java.lang.Number> double average(java.util.Collection<T> values)

intersect

public static <T> java.util.Collection<T> intersect(java.util.Collection<T> a,
                                                    java.util.Collection<T> b)

union

public static <T> java.util.Collection<T> union(java.util.Collection<T> a,
                                                java.util.Collection<T> b)

parseInteger

public static java.lang.Integer parseInteger(java.lang.String string)