@Test
public void calculatesNorm() {

    final Decimal field = new Decimal();
    final Dot dot = new Dot();
    MatcherAssert.assertThat(
        field.actual(dot.norm(new DblVect(1., 0.))),
        Matchers.equalTo(1.)
    );
    MatcherAssert.assertThat(
        field.actual(dot.norm(new DblVect(0., 0.))),
        Matchers.equalTo(0.)
    );
    MatcherAssert.assertThat(
        field.actual(dot.norm(new DblVect(1., 1.))),
        Matchers.equalTo(Math.sqrt(2.))
    );
    final double expected = Math.sqrt(8);
    final double mintwo = -2.;
    MatcherAssert.assertThat(
        field.actual(dot.norm(new DblVect(mintwo, mintwo))),
        Matchers.equalTo(expected)
    );
}