public void CreateDiscrete()
{
/*
* 5 3 0 1
* 4 0 0 1
* 1 1 0 5
* 1 0 0 4
* 0 1 5 4
*/
DataMatrix R = GetSampleRatingMatrix();
// act
PrefRelations PR = PrefRelations.CreateDiscrete(R);
// assert
foreach (KeyValuePair <int, SparseMatrix> user in PR.PreferenceRelationsByUser)
{
int indexOfUser = user.Key;
SparseMatrix preferencesOfUser = user.Value;
// Note that the diagonal (item compares to itsself) is elft empty
Debug.Assert(preferencesOfUser.Trace() == 0);
// Check if the correct number of preference relations have been created
Debug.Assert((Math.Pow(R.GetNonZerosCountOfRow(indexOfUser), 2)
- R.GetNonZerosCountOfRow(indexOfUser))
== preferencesOfUser.NonZerosCount);
}
// Check if the first user's preferences are correct
Debug.WriteLine("PR[0][0, 0]=" + PR[0][0, 0]);
Debug.Assert(PR[0][0, 0] == SparseMatrix.Zero);
Debug.Assert(PR[0][0, 1] == Config.Preferences.Preferred);
Debug.Assert(PR[0][1, 0] == Config.Preferences.LessPreferred);
Debug.Assert(PR[0][0, 2] == SparseMatrix.Zero);
Debug.Assert(PR[0][2, 0] == SparseMatrix.Zero);
Debug.Assert(PR[0][1, 2] == SparseMatrix.Zero);
Debug.Assert(PR[0][2, 1] == SparseMatrix.Zero);
Debug.Assert(PR[0][1, 3] == Config.Preferences.Preferred);
Debug.Assert(PR[0][3, 1] == Config.Preferences.LessPreferred);
// Check if the last user's preferences are correct
Debug.Assert(PR[4][1, 1] == SparseMatrix.Zero);
Debug.Assert(PR[4][0, 1] == SparseMatrix.Zero);
Debug.Assert(PR[4][1, 0] == SparseMatrix.Zero);
Debug.Assert(PR[4][0, 2] == SparseMatrix.Zero);
Debug.Assert(PR[4][2, 0] == SparseMatrix.Zero);
Debug.Assert(PR[4][1, 2] == Config.Preferences.LessPreferred);
Debug.Assert(PR[4][2, 1] == Config.Preferences.Preferred);
Debug.Assert(PR[4][1, 3] == Config.Preferences.LessPreferred);
Debug.Assert(PR[4][3, 1] == Config.Preferences.Preferred);
}
public void PreferencesToPositions()
{
/*
* 5 3 0 1
* 4 0 0 1
* 1 1 0 5
* 1 0 0 4
* 0 1 5 4
*/
DataMatrix R = GetSampleRatingMatrix();
PrefRelations PR = PrefRelations.CreateDiscrete(R);
// act
// Convert first, Third, and last users' preferences to positions
Vector <double> positionsOfUserFirst = PR.PreferencesToPositions(PR[0]);
Vector <double> positionsOfUserThird = PR.PreferencesToPositions(PR[2]);
Vector <double> positionsOfUserLast = PR.PreferencesToPositions(PR[4]);
// assert
// Check first user
Debug.Assert(positionsOfUserFirst[0] == 1 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserFirst[1] == 0 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserFirst[2] == SparseMatrix.Zero);
Debug.Assert(positionsOfUserFirst[3] == -1 + Config.Preferences.PositionShift);
// Check third user
Debug.Assert(positionsOfUserThird[0] == -0.5 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserThird[1] == -0.5 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserThird[2] == SparseMatrix.Zero);
Debug.Assert(positionsOfUserThird[3] == 1 + Config.Preferences.PositionShift);
// Check second last user
Debug.Assert(positionsOfUserLast[0] == SparseMatrix.Zero);
Debug.Assert(positionsOfUserLast[1] == -1 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserLast[2] == 1 + Config.Preferences.PositionShift);
Debug.Assert(positionsOfUserLast[3] == 0 + Config.Preferences.PositionShift);
// The number of positions should match the number of ratings by each user
Debug.Assert(positionsOfUserFirst.GetNonZerosCount()
== R.GetNonZerosCountOfRow(0), String.Format("{0}=={1}",
positionsOfUserFirst.GetNonZerosCount(), R.GetNonZerosCountOfRow(0)));
Debug.Assert(positionsOfUserThird.GetNonZerosCount()
== R.GetNonZerosCountOfRow(2), String.Format("{0}=={1}",
positionsOfUserThird.GetNonZerosCount(), R.GetNonZerosCountOfRow(2)));
Debug.Assert(positionsOfUserLast.GetNonZerosCount()
== R.GetNonZerosCountOfRow(4), String.Format("{0}=={1}",
positionsOfUserLast.GetNonZerosCount(), R.GetNonZerosCountOfRow(4)));
}