public void DeterminantException()
{
MatrixD a = new MatrixD(new double[, ] {
{ 1, 2 }, { 5, 6 }, { 0, 1 }
});
LUDecompositionD d = new LUDecompositionD(a);
double det = d.Determinant();
}
public void TestSingularMatrix()
{
MatrixD a = new MatrixD(new double[, ] {
{ 1, 2, 3 }, { 4, 5, 6 }, { 5, 7, 9 }
});
LUDecompositionD d = new LUDecompositionD(a);
Assert.AreEqual(true, d.IsNumericallySingular);
Assert.IsTrue(Numeric.IsZero(d.Determinant()));
}
public void Determinant()
{
MatrixD a = new MatrixD(new double[, ] {
{ 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 0, 1, 2, 0 }, { 1, 0, 1, 0 }
});
LUDecompositionD d = new LUDecompositionD(a);
Assert.AreEqual(false, d.IsNumericallySingular);
Assert.IsTrue(Numeric.AreEqual(-24, d.Determinant()));
MatrixD aPermuted = d.L * d.U;
Assert.IsTrue(MatrixD.AreNumericallyEqual(aPermuted, a.GetSubmatrix(d.PivotPermutationVector, 0, 3)));
}