/// <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;
}
/// <summary>Read in rating test data (Track 1) from a TextReader</summary>
/// <param name="reader">the <see cref="StreamReader"/> to read from</param>
/// <returns>the rating data</returns>
static public IRatings ReadTest(StreamReader reader)
{
IRatings ratings = new StaticByteRatings(GetNumberOfRatings(reader));
string line;
while ( (line = reader.ReadLine()) != null )
{
string[] tokens = line.Split('|');
int user_id = int.Parse(tokens[0]);
int num_user_ratings = int.Parse(tokens[1]); // number of ratings for this user
for (int i = 0; i < num_user_ratings; i++)
{
line = reader.ReadLine();
tokens = line.Split('\t');
int item_id = int.Parse(tokens[0]);
ratings.Add(user_id, item_id, 0);
}
}
return ratings;
}
public void TestFull()
{
var ratings = new StaticByteRatings(2);
Assert.AreEqual(0, ratings.Count);
ratings.Add(1, 4, 3);
Assert.AreEqual(1, ratings.Count);
ratings.Add(1, 8, 2);
Assert.AreEqual(2, ratings.Count);
ratings.Add(2, 4, 2);
}
[Test()] public void TestMaxUserIDMaxItemID()
{
var ratings = new StaticByteRatings(7);
ratings.Add(1, 4, 3);
ratings.Add(1, 8, 2);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 7, 2);
ratings.Add(6, 3, 3);
Assert.AreEqual(6, ratings.MaxUserID);
Assert.AreEqual(8, ratings.MaxItemID);
}
[Test()] public void TestMinRatingMaxRating()
{
var ratings = new StaticByteRatings(7);
ratings.Add(1, 4, 3);
ratings.Add(1, 8, 2);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 7, 2);
ratings.Add(6, 3, 3);
Assert.AreEqual(6, ratings.Scale.Max);
Assert.AreEqual(2, ratings.Scale.Min);
}
[Test()] public void TestAdd()
{
var ratings = new StaticByteRatings(7);
ratings.Add(1, 4, 3);
Assert.AreEqual(1, ratings.Count);
ratings.Add(1, 8, 2);
Assert.AreEqual(2, ratings.Count);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 7, 2);
ratings.Add(6, 3, 3);
Assert.AreEqual(4, ratings[2, 5]);
Assert.AreEqual(3, ratings[1, 4]);
Assert.AreEqual(3, ratings[6, 3]);
Assert.AreEqual(7, ratings.Count);
}
public void TestAddRating()
{
var ratings = new StaticByteRatings(7);
ratings.Add(1, 4, 3);
Assert.AreEqual(1, ratings.Count);
ratings.Add(1, 8, 2);
Assert.AreEqual(2, ratings.Count);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 7, 2);
ratings.Add(6, 3, 3);
Assert.AreEqual(4, ratings.Get(2, 5));
Assert.AreEqual(3, ratings.Get(1, 4));
Assert.AreEqual(3, ratings.Get(6, 3));
Assert.AreEqual(7, ratings.Count);
}
/// <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>
/// <param name="ignore_first_line">if true, ignore the first line</param>
/// <returns>the rating data</returns>
public static IRatings Read(
TextReader reader, int size,
IEntityMapping user_mapping = null, IEntityMapping item_mapping = null,
RatingType rating_type = RatingType.FLOAT,
bool ignore_first_line = false)
{
if (user_mapping == null)
user_mapping = new IdentityMapping();
if (item_mapping == null)
item_mapping = new IdentityMapping();
if (ignore_first_line)
reader.ReadLine();
IRatings ratings;
if (rating_type == RatingType.BYTE)
ratings = new StaticByteRatings(size);
else if (rating_type == RatingType.FLOAT)
ratings = new StaticRatings(size);
else
throw new FormatException(string.Format("Unknown rating type: {0}", rating_type));
string line;
while ((line = reader.ReadLine()) != null)
{
if (line.Length == 0)
continue;
string[] tokens = line.Split(Constants.SPLIT_CHARS);
if (tokens.Length < 3)
throw new FormatException("Expected at least 3 columns: " + line);
int user_id = user_mapping.ToInternalID(tokens[0]);
int item_id = item_mapping.ToInternalID(tokens[1]);
float rating = float.Parse(tokens[2], CultureInfo.InvariantCulture);
ratings.Add(user_id, item_id, rating);
}
return ratings;
}
/// <summary>Read in rating data from a TextReader</summary>
/// <param name="reader">the <see cref="StreamReader"/> to read from</param>
/// <returns>the rating data</returns>
static public IRatings Read80Plus(StreamReader reader)
{
// create ratings data structure
IRatings ratings = new StaticByteRatings(GetNumberOfRatings(reader));
// read in ratings
string line;
while ( (line = reader.ReadLine()) != null )
{
string[] tokens = line.Split('|');
int user_id = int.Parse(tokens[0]);
int num_user_ratings = int.Parse(tokens[1]); // number of ratings for this user
for (int i = 0; i < num_user_ratings; i++)
{
line = reader.ReadLine();
tokens = line.Split('\t');
int item_id = int.Parse(tokens[0]);
byte rating = byte.Parse(tokens[1]);
ratings.Add(user_id, item_id, rating >= 80 ? 1 : 0);
}
}
return ratings;
}
public void TestRemoveAt()
{
var ratings = new StaticByteRatings(8);
ratings.Add(1, 4, 3);
ratings.Add(1, 8, 2);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 7, 2);
ratings.Add(3, 3, 3);
ratings.Add(6, 3, 3);
Assert.AreEqual(8, ratings.Count);
ratings.RemoveAt(ratings.GetIndex(2, 5));
}
[Test()] public void TestIndex()
{
var ratings = new StaticByteRatings(8);
ratings.Add(1, 4, 3);
ratings.Add(1, 8, 2);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 4, 2);
ratings.Add(3, 3, 3);
ratings.Add(6, 3, 3);
// test index[,]
Assert.AreEqual(3, ratings[1, 4]);
Assert.AreEqual(2, ratings[1, 8]);
Assert.AreEqual(6, ratings[2, 2]);
}
public void TestRemoveItem()
{
var ratings = new StaticByteRatings(7);
ratings.Add(1, 4, 3);
ratings.Add(1, 8, 2);
ratings.Add(2, 4, 2);
ratings.Add(2, 2, 6);
ratings.Add(2, 5, 4);
ratings.Add(3, 4, 2);
ratings.Add(3, 3, 3);
Assert.AreEqual(7, ratings.Count);
ratings.RemoveItem(4);
}
