public void DerivativeTest() { double beta = 0.52; double constant = 2.42; double[] expected = { 5.84785, 6.15998, 6.48877, 6.83512, 7.19995, 7.58425, 7.98906, 8.41549, 8.86467, 9.33783, 9.83624 }; LogLinkFunction target = new LogLinkFunction(beta, constant); for (int i = 0; i < 11; i++) { double x = i / 10.0; double y = target.Inverse(x); double d1 = target.Derivative(x); double d2 = target.Derivative2(y); Assert.AreEqual(expected[i], d1, 1e-5); Assert.AreEqual(expected[i], d2, 1e-5); Assert.IsFalse(Double.IsNaN(d1)); Assert.IsFalse(Double.IsNaN(d2)); } }