Inverse() 공개 메소드

The Probit mean (activation) function.
The Probit link function is given by g(x) = Phi(x), in which Phi is the Normal (Gaussian) cumulative distribution function.
public Inverse ( double x ) : double
x double A transformed value.
리턴 double
ProbitLinkFunction 1 문서
예제 #1
0
        public void ProbitLinkFunctionConstructorTest()
        {
            ProbitLinkFunction target = new ProbitLinkFunction();

            double[] expected = 
            {
                Double.NegativeInfinity, -1.28155, -0.841621, -0.524401, -0.253347,
                0, 0.253347, 0.524401, 0.841621, 1.28155, Double.PositiveInfinity
            };

            for (int i = 0; i < 11; i++)
            {
                double x = i / 10.0;
                double y = expected[i];

                double fx = target.Function(x);
                double iy = target.Inverse(y);

                Assert.AreEqual(y, fx, 1e-5);
                Assert.AreEqual(x, iy, 1e-5);

                Assert.IsFalse(Double.IsNaN(fx));
                Assert.IsFalse(Double.IsNaN(iy));
            }
        }
예제 #2
0
        public void DerivativeTest()
        {
            ProbitLinkFunction target = new ProbitLinkFunction();

            double[] expected = 
            {
                0.398942, 0.396953, 0.391043, 0.381388, 0.36827, 0.352065,
                0.333225, 0.312254, 0.289692, 0.266085, 0.241971
            };

            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));
            }
        }