// Z pliku binarnego, jeśli istnieje
public ALS(int iloscFaktorow, String FileName)
{
R = Serializer.UnpackRMatrix(FileName);
U = new Matrix(iloscFaktorow, R.u);
U.FillRandom();
P = new Matrix(iloscFaktorow, R.p);
P.FillRandom();
countOfFactors = iloscFaktorow;
}
// Z pliku txt, jeśli istnieje
public ALS(int iloscFaktorow, int iloscProduktow, int iloscUserow)
{
R = Extractor.createR(iloscProduktow, iloscUserow);
Serializer.PackRMatrix(R);
U = new Matrix(iloscFaktorow, R.u);
U.FillRandom();
P = new Matrix(iloscFaktorow, R.p);
P.FillRandom();
countOfFactors = iloscFaktorow;
}
public static void Calculate(int d, RMatrix R, Matrix U, Matrix P, double lambda)
{
double sum1 = 0;
foreach (var kvp in R.ratings)
{
double r_up = kvp.Value;
int u = kvp.Key.Item1;
int p = kvp.Key.Item2;
double vectorSum = 0;
for (int row = 0; row < d; row++)
{
vectorSum += U.Data[row, u] * P.Data[row, p];
}
sum1 += Math.Pow(r_up + vectorSum, 2);
}
double sum2 = 0;
for (int col = 0; col < U.ColumnCount; col++)
{
double vectorSum = 0;
for (int row = 0; row < d; row++)
{
vectorSum += Math.Pow(U.Data[row, col], 2);
}
sum2 += vectorSum;
}
double sum3 = 0;
for (int col = 0; col < P.ColumnCount; col++)
{
double vectorSum = 0;
for (int row = 0; row < d; row++)
{
vectorSum += Math.Pow(P.Data[row, col], 2);
}
sum3 += vectorSum;
}
double total = sum1 + lambda * (sum2 + sum3);
//Console.WriteLine($"sum1 = ${sum1}, sum2 = ${sum2}, sum3 = ${sum3}, total = ${total}");
Console.WriteLine(total);
}
public RMatrix extractToR()
{
RMatrix r = new RMatrix();
int standardItemID = 0;
foreach (Item item in items)
{
foreach (Tuple <string, int> ratingTuple in item.Rates)
{
r.Add(users[ratingTuple.Item1], standardItemID, ratingTuple.Item2);
}
standardItemID++;
}
r.setSize(users.Count, items.Count);
return(r);
}
public static void PackRMatrix(RMatrix rMatrix)
{
Pack(rMatrix, "p" + rMatrix.p + "u" + rMatrix.u);
}