public void ToVector4D()
{
VectorD v = new VectorD(new[] { 1.1, 2.2, 3.3, 4.4 });
Vector4D u = v.ToVector4D();
Assert.AreEqual(1.1, u[0]);
Assert.AreEqual(2.2, u[1]);
Assert.AreEqual(3.3, u[2]);
Assert.AreEqual(4.4, u[3]);
}