public void ToArray2D() { Matrix33D m = new Matrix33D(1, 2, 3, 4, 5, 6, 7, 8, 9); double[,] array = m.ToArray2D(); for (int i = 0; i < 3; i++) for (int j = 0; j < 3; j++) Assert.AreEqual(i * 3 + j + 1, array[i, j]); array = (double[,])m; for (int i = 0; i < 3; i++) for (int j = 0; j < 3; j++) Assert.AreEqual(i * 3 + j + 1, array[i, j]); }