public void AddToDiagTest1()
{
double[,] a =
{
{ 2, 5, -1 },
{ 5, 0, 2 },
};
double[,] expected =
{
{ 3, 5, -1 },
{ 5, 1, 2 },
};
double[,] actual = Matrix.AddToDiagonal(a, 1.0);
Assert.IsTrue(expected.IsEqual(actual));
actual = Elementwise.SubtractFromDiagonal(actual, 1.0);
Assert.IsTrue(actual.IsEqual(a));
}