}
@Test
public void testNormXY() {
final Vector3 a = new Vector3(1., 2., 3.);
a.xynorm();
assertEquals(1., a.x);
assertEquals(2., a.y);
assertEquals(3., a.z);
assertEquals(Math.sqrt(5), new Vector3(1., 2., Double.NaN).xynorm());
assertEquals(Math.sqrt(5), new Vector3(2., 1., Double.NaN).xynorm());