public void DeterminantTest()
{
double[,] value =
{
{ 6, -1, 2, 1 },
{ -1, 9, -3, -2 },
{ 2, -3, 8, 1 },
{ 1, -2, 1, 7 },
};
var chol = new JaggedCholeskyDecomposition(value.ToJagged());
Assert.AreEqual(2232, chol.Determinant, 1e-12);
Assert.IsTrue(chol.Nonsingular);
//Assert.IsTrue(chol.Symmetric);
}