Accord.Statistics.Links.ProbitLinkFunction.Inverse C# (CSharp) Method

Inverse() public method

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.
return double
        public double Inverse(double x)
        {
            return Normal.Function(x);
        }

Usage Example

        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));
            }
        }
All Usage Examples Of Accord.Statistics.Links.ProbitLinkFunction::Inverse