@Test public void testMeanCalculation() { Mean a = new Mean(); a.add(1); assertEquals(1, a.count()); assertEquals(1d, a.mean(), 0.00001d); a.add(1); assertEquals(2, a.count()); assertEquals(1d, a.mean(), 0.00001d); a.toString(); Mean b = new Mean(); b.add(0.5); assertEquals(1, b.count()); assertEquals(0.5d, b.mean(), 0.00001d); b.add(2); assertEquals(2, b.count()); assertEquals(1.25d, b.mean(), 0.00001d); b.toString(); Mean c = new Mean(); assertEquals(0, c.count()); assertEquals(0d, c.mean(), 0.00001d); c.toString(); }