/// <summary>Read in static rating data from a TextReader</summary>
/// <param name="reader">the <see cref="TextReader"/> to read from</param>
/// <param name="size">the number of ratings in the file</param>
/// <param name="user_mapping">mapping object for user IDs</param>
/// <param name="item_mapping">mapping object for item IDs</param>
/// <param name="rating_type">the data type to be used for storing the ratings</param>
/// <returns>the rating data</returns>
public static IRatings Read(TextReader reader, int size,
IEntityMapping user_mapping, IEntityMapping item_mapping,
RatingType rating_type)
{
IRatings ratings;
if (rating_type == RatingType.BYTE)
ratings = new StaticByteRatings(size);
else if (rating_type == RatingType.FLOAT)
ratings = new StaticFloatRatings(size);
else
ratings = new StaticRatings(size);
var split_chars = new char[]{ '\t', ' ', ',' };
string line;
while ( (line = reader.ReadLine()) != null )
{
if (line.Length == 0)
continue;
string[] tokens = line.Split(split_chars);
if (tokens.Length < 3)
throw new IOException("Expected at least three columns: " + line);
int user_id = user_mapping.ToInternalID(int.Parse(tokens[0]));
int item_id = item_mapping.ToInternalID(int.Parse(tokens[1]));
double rating = double.Parse(tokens[2], CultureInfo.InvariantCulture);
ratings.Add(user_id, item_id, rating);
}
return ratings;
}
public void TestAddRating()
{
var ratings = new StaticFloatRatings(7);
ratings.Add(1, 4, 0.3f);
Assert.AreEqual(1, ratings.Count);
ratings.Add(1, 8, 0.2f);
Assert.AreEqual(2, ratings.Count);
ratings.Add(2, 4, 0.2f);
ratings.Add(2, 2, 0.6f);
ratings.Add(2, 5, 0.4f);
ratings.Add(3, 7, 0.2f);
ratings.Add(6, 3, 0.3f);
Assert.AreEqual(0.4f, ratings.Get(2, 5));
Assert.AreEqual(0.3f, ratings.Get(1, 4));
Assert.AreEqual(0.3f, ratings.Get(6, 3));
Assert.AreEqual(7, ratings.Count);
}
public void TestRemoveUser()
{
var ratings = new StaticFloatRatings(7);
ratings.Add(1, 4, 0.3);
ratings.Add(1, 8, 0.2);
ratings.Add(2, 4, 0.2);
ratings.Add(2, 2, 0.6);
ratings.Add(2, 5, 0.4);
ratings.Add(3, 7, 0.2);
ratings.Add(3, 3, 0.3);
Assert.AreEqual(7, ratings.Count);
ratings.RemoveUser(2);
}
public void TestRemoveAt()
{
var ratings = new StaticFloatRatings(8);
ratings.Add(1, 4, 0.3);
ratings.Add(1, 8, 0.2);
ratings.Add(2, 4, 0.2);
ratings.Add(2, 2, 0.6);
ratings.Add(2, 5, 0.4);
ratings.Add(3, 7, 0.2);
ratings.Add(3, 3, 0.3);
ratings.Add(6, 3, 0.3);
Assert.AreEqual(8, ratings.Count);
ratings.RemoveAt(ratings.GetIndex(2, 5));
}
public void TestMaxUserIDMaxItemID()
{
var ratings = new StaticFloatRatings(7);
ratings.Add(1, 4, 0.3);
ratings.Add(1, 8, 0.2);
ratings.Add(2, 4, 0.2);
ratings.Add(2, 2, 0.6);
ratings.Add(2, 5, 0.4);
ratings.Add(3, 7, 0.2);
ratings.Add(6, 3, 0.3);
Assert.AreEqual(6, ratings.MaxUserID);
Assert.AreEqual(8, ratings.MaxItemID);
}
public void TestGet()
{
var ratings = new StaticFloatRatings(8);
ratings.Add(1, 4, 0.3f);
ratings.Add(1, 8, 0.2f);
ratings.Add(2, 4, 0.2f);
ratings.Add(2, 2, 0.6f);
ratings.Add(2, 5, 0.4f);
ratings.Add(3, 4, 0.2f);
ratings.Add(3, 3, 0.3f);
ratings.Add(6, 3, 0.3f);
// test Get
Assert.AreEqual(0.2f, ratings.Get(2, 4));
Assert.AreEqual(0.3f, ratings.Get(3, 3));
Assert.AreEqual(0.3f, ratings.Get(6, 3));
// test index[,]
Assert.AreEqual(0.3f, ratings[1, 4]);
Assert.AreEqual(0.2f, ratings[1, 8]);
Assert.AreEqual(0.6f, ratings[2, 2]);
}
public void TestFull()
{
var ratings = new StaticFloatRatings(2);
Assert.AreEqual(0, ratings.Count);
ratings.Add(1, 4, 0.3);
Assert.AreEqual(1, ratings.Count);
ratings.Add(1, 8, 0.2);
Assert.AreEqual(2, ratings.Count);
ratings.Add(2, 4, 0.2);
}
