/// <summary>
/// Initializes a new instance of the <see cref="UserEvd"/> class. This object will compute the
/// the eigenvalue decomposition when the constructor is called and cache it's decomposition.
/// </summary>
/// <param name="matrix">The matrix to factor.</param>
/// <param name="symmetricity">If it is known whether the matrix is symmetric or not the routine can skip checking it itself.</param>
/// <exception cref="ArgumentNullException">If <paramref name="matrix"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentException">If EVD algorithm failed to converge with matrix <paramref name="matrix"/>.</exception>
public static UserEvd Create(Matrix<double> matrix, Symmetricity symmetricity)
{
if (matrix.RowCount != matrix.ColumnCount)
{
throw new ArgumentException(Resources.ArgumentMatrixSquare);
}
var order = matrix.RowCount;
// Initialize matricies for eigenvalues and eigenvectors
var eigenVectors = Matrix<double>.Build.SameAs(matrix, order, order);
var blockDiagonal = Matrix<double>.Build.SameAs(matrix, order, order);
var eigenValues = new LinearAlgebra.Complex.DenseVector(order);
bool isSymmetric;
switch (symmetricity)
{
case Symmetricity.Symmetric:
case Symmetricity.Hermitian:
isSymmetric = true;
break;
case Symmetricity.Asymmetric:
isSymmetric = false;
break;
default:
isSymmetric = matrix.IsSymmetric();
break;
}
var d = new double[order];
var e = new double[order];
if (isSymmetric)
{
matrix.CopyTo(eigenVectors);
d = eigenVectors.Row(order - 1).ToArray();
SymmetricTridiagonalize(eigenVectors, d, e, order);
SymmetricDiagonalize(eigenVectors, d, e, order);
}
else
{
var matrixH = matrix.ToArray();
NonsymmetricReduceToHessenberg(eigenVectors, matrixH, order);
NonsymmetricReduceHessenberToRealSchur(eigenVectors, matrixH, d, e, order);
}
for (var i = 0; i < order; i++)
{
blockDiagonal.At(i, i, d[i]);
if (e[i] > 0)
{
blockDiagonal.At(i, i + 1, e[i]);
}
else if (e[i] < 0)
{
blockDiagonal.At(i, i - 1, e[i]);
}
}
for (var i = 0; i < order; i++)
{
eigenValues[i] = new Complex(d[i], e[i]);
}
return new UserEvd(eigenVectors, eigenValues, blockDiagonal, isSymmetric);
}
public void IsSymmetricTest()
{
double[,] data = null; // TODO: инициализация подходящего значения
Matrix target = new Matrix(data); // TODO: инициализация подходящего значения
bool expected = false; // TODO: инициализация подходящего значения
bool actual;
actual = target.IsSymmetric();
Assert.AreEqual(expected, actual);
Assert.Inconclusive("Проверьте правильность этого метода теста.");
}
