public void MultiplyByDiagonalTest()
{
double[,] A =
{
{ 4, 1, 2 },
{ 5, 6, 5 },
};
double[,] B =
{
{ 1, 0, 0 },
{ 0, 2, 0 },
{ 0, 0, 3 },
};
double[] b = B.Diagonal();
double[,] expected = Matrix.Multiply(A, B);
double[,] actual = A.MultiplyByDiagonal(b);
Assert.IsTrue(expected.IsEqual(actual));
}