public static MMatrix Floor(MMatrix A)
{
MMatrix B = A.Clone();
for (int i = 0; i < B.row; ++i)
for (int j = 0; j < B.col; ++j)
B[i, j] = Math.Floor(B[i,j]);
return B;
}
public static double SpectralRadius_Jacobi(MMatrix A)
{
Vector Eigenvalues = new Vector();
MMatrix Eigenvectors = new MMatrix();
MMatrix temp = A.Clone();
temp.Jacobi_Cyclic_Method(ref Eigenvalues, ref Eigenvectors);
Eigenvalues.Sort(true);
return Math.Abs(Eigenvalues[0]);
}
//A = P^1*L*U = Pt*L*U
private static void FactorLU_withP(MMatrix matrix, int size)
{
MMatrix A = matrix.Clone();
MMatrix P = MMatrix.DiagonalMatrix(size, 1);
A.LU_L = new double[size, size];
for (int i = 0; i < size; ++i)
A.LU_L[i, i] = 1;
for (int i = 0; i < size; ++i)
{
//Interchange row if the entry [i,i] is 0
if (A[i, i] == 0) // if diagonal entry is zero,
for (int k = i + 1; k < A.row; ++k)
if (A[k, i] != 0) //check if some below entry is non-zero
{
A.InterchangeRow(i, k); // then interchange the two rows
P.InterchangeRow(i, k);
}
if (A[i, i] == 0) // if not found any non-zero diagonal entry
throw new MMatrixException("Cannot factor LU for this matrix");
for (int j = i + 1; j < size; ++j)
{
A.LU_L[j, i] = A[j, i] / A[i, i];
A.AddRow(j, i, -A.LU_L[j, i]);
}
}
matrix.LU_P = P.MArray;
matrix.LU_L = A.LU_L;
matrix.LU_U = A.MArray;
}
public SystemOfEquation(MMatrix CoefficientMatrix, Vector b)
{
this.CoefficientMatrix = CoefficientMatrix.Clone();
this.b = b.Clone();
}