/// <summary>
/// Adds two matrixes
/// </summary>
/// <param name="mtx1">first matrix</param>
/// <param name="mtx2">second matrix</param>
/// <returns>result of summing this matrixes</returns>
public static KnuthSparseMatrix operator +(KnuthSparseMatrix mtx1, KnuthSparseMatrix mtx2)
{
if (mtx1.storage.Rows.Count != mtx2.storage.Rows.Count || mtx1.storage.Cols.Count != mtx2.storage.Cols.Count)
throw new Exception("Wrong size of matrix to summ");
KnuthSparseMatrix Res = new KnuthSparseMatrix(mtx1.storage.Rows.Count, mtx1.storage.Cols.Count);
KnuthNode<double> Iter1, Iter2;
for (int i = 0; i < mtx1.storage.Rows.Count; ++i)
{
Iter1 = mtx1.storage.Rows[i].Left;
Iter2 = mtx2.storage.Rows[i].Left;
while (Iter1 != mtx1.storage.Rows[i] || Iter2 != mtx2.storage.Rows[i])
{
if (Iter1 == mtx1.storage.Rows[i])
{
Res.At(Iter2.Row, Iter2.Col, Iter2.Val);
Iter2 = Iter2.Left;
}
else if (Iter2 == mtx2.storage.Rows[i])
{
Res.At(Iter1.Row, Iter1.Col, Iter1.Val);
Iter1 = Iter1.Left;
}
else if (Iter1.Col == Iter2.Col)
{
Res.At(Iter1.Row, Iter1.Col, Iter1.Val + Iter2.Val);
Iter1 = Iter1.Left;
Iter2 = Iter2.Left;
}
else if (Iter1.Col < Iter2.Col)
{
Res.At(Iter2.Row, Iter2.Col, Iter2.Val);
Iter2 = Iter2.Left;
}
else //(Iter2.Col < Iter1.Col)
{
Res.At(Iter1.Row, Iter1.Col, Iter1.Val);
Iter1 = Iter1.Left;
}
}
}
return Res;
}
/// <summary>
/// Multiply two sparse matrix
/// </summary>
/// <param name="mtx1">first matrix</param>
/// <param name="mtx2">second matrix</param>
/// <returns>result of multiplying this matrix</returns>
public static KnuthSparseMatrix operator *(KnuthSparseMatrix mtx1, KnuthSparseMatrix mtx2)
{
if (mtx1.storage.Cols.Count != mtx2.storage.Rows.Count)
throw new Exception("Wrong size of matrix to multiple");
KnuthSparseMatrix Res = new KnuthSparseMatrix(mtx1.storage.Rows.Count, mtx2.storage.Cols.Count);
double tmp;
KnuthNode<double> Iter1, Iter2;
for (int i = 0; i < mtx1.storage.Rows.Count; ++i)
{
for (int j = 0; j < mtx2.storage.Cols.Count; ++j)
{
tmp = 0; //initalize mult of i-th row and j-th column
Iter1 = mtx1.storage.Rows[i].Left;
Iter2 = mtx2.storage.Cols[j].Up;
while (Iter1 != mtx1.storage.Rows[i] && Iter2 != mtx2.storage.Cols[j])
{
if (Iter1.Col == Iter2.Row)
{
tmp += Iter1.Val * Iter2.Val;
Iter1 = Iter1.Left;
Iter2 = Iter2.Up;
}
else if (Iter1.Col < Iter2.Row)
{
Iter2 = Iter2.Up;
}
else //(Iter2.Col < Iter1.Col)
{
Iter1 = Iter1.Left;
}
}
if (tmp != 0) // paste not 0 element
{
Res.At(i, j, tmp);
}
}
}
return Res;
}