public void Main()
{
// Create a matrix containing the
// lower triangular part of the Hermitian matrix
// whose eigenvalues must be computed.
var matrix = ComplexMatrix.Dense(2, 2, new Complex[4] {
new Complex(1, 0), new Complex(-3, -2),
new Complex(5, 4), new Complex(-6, 0)
}, StorageOrder.RowMajor);
// Set the relevant triangular part.
bool lowerTriangularPart = false;
// Compute the eigenvalues.
var eigenvalues = SpectralDecomposition.GetEigenvalues(
matrix,
lowerTriangularPart);
Console.WriteLine("Matrix whose eigenvalues must be computed:");
Console.WriteLine(ComplexMatrix.Dense(2, 2, new Complex[4] {
new Complex(1, 0), new Complex(-3, -2),
new Complex(-3, 2), new Complex(-6, 0)
}, StorageOrder.RowMajor));
Console.WriteLine("Matrix eigenvalues:");
Console.WriteLine(eigenvalues);
}
/// <summary>
/// Tests the operation
/// when its operand is set through a value represented by a <b>null</b> instance.
/// </summary>
public static void MatrixIsNull()
{
ArgumentExceptionAssert.Throw(
() =>
{
SpectralDecomposition.GetEigenvalues(
matrix: (DoubleMatrix)null,
lowerTriangularPart: true);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "matrix");
ArgumentExceptionAssert.Throw(
() =>
{
SpectralDecomposition.GetEigenvalues(
matrix: (ReadOnlyDoubleMatrix)null,
lowerTriangularPart: true);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "matrix");
ArgumentExceptionAssert.Throw(
() =>
{
SpectralDecomposition.GetEigenvalues(
matrix: (ComplexMatrix)null,
lowerTriangularPart: true);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "matrix");
ArgumentExceptionAssert.Throw(
() =>
{
SpectralDecomposition.GetEigenvalues(
matrix: (ReadOnlyComplexMatrix)null,
lowerTriangularPart: true);
},
expectedType: typeof(ArgumentNullException),
expectedPartialMessage: ArgumentExceptionAssert.NullPartialMessage,
expectedParameterName: "matrix");
}
/// Tests that method
/// <see cref="SpectralDecomposition
/// .GetEigenvalues(ComplexMatrix)"/>,
/// method has
/// been properly implemented.
public static void Succeed(
TestableSpectralDecomposition <TestableComplexMatrix, ComplexMatrix> testableSD)
{
var testableMatrix = testableSD.TestableMatrix;
#region Writable
// Dense, Lower
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsDense,
lowerTriangularPart: true);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Sparse, Lower
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsSparse,
lowerTriangularPart: true);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Dense, Upper
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsDense,
lowerTriangularPart: false);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Sparse, Upper
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsSparse,
lowerTriangularPart: false);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
#endregion
#region ReadOnly
// Dense, Lower
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsDense.AsReadOnly(),
lowerTriangularPart: true);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Sparse, Lower
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsSparse.AsReadOnly(),
lowerTriangularPart: true);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Dense, Upper
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsDense.AsReadOnly(),
lowerTriangularPart: false);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
// Sparse, Upper
{
var actualValues = SpectralDecomposition.GetEigenvalues(
testableMatrix.AsSparse.AsReadOnly(),
lowerTriangularPart: false);
DoubleMatrixAssert.AreEqual(
expected: GetMainDiagonal(testableSD.Values),
actual: actualValues,
delta: SpectralDecompositionTest.Accuracy);
}
#endregion
}