public void DerivativeTest()
{
double beta = 3.14;
double constant = 2.91;
double[] expected =
{
-0.316272, -0.271211, -0.235919, -0.207668, -0.184638,
-0.16557, -0.149573, -0.135995, -0.124354, -0.114284, -0.105503
};
InverseSquaredLinkFunction target = new InverseSquaredLinkFunction(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-6);
Assert.AreEqual(expected[i], d2, 1e-6);
Assert.IsFalse(Double.IsNaN(d1));
Assert.IsFalse(Double.IsNaN(d2));
}
}
public static ILinkFunction Get(LinkFunctionType link)
{
ILinkFunction result = null;
switch (link)
{
case LinkFunctionType.Absolute: result = new AbsoluteLinkFunction(); break;
case LinkFunctionType.Cauchit: result = new CauchitLinkFunction(); break;
case LinkFunctionType.Identity: result = new IdentityLinkFunction(); break;
case LinkFunctionType.Inverse: result = new InverseLinkFunction(); break;
case LinkFunctionType.InverseSquared: result = new InverseSquaredLinkFunction(); break;
case LinkFunctionType.Logit: result = new LogitLinkFunction(); break;
case LinkFunctionType.Log: result = new LogLinkFunction(); break;
case LinkFunctionType.LogLog: result = new LogLogLinkFunction(); break;
case LinkFunctionType.Probit: result = new ProbitLinkFunction(); break;
case LinkFunctionType.Sin: result = new SinLinkFunction(); break;
case LinkFunctionType.Threshold: result = new ThresholdLinkFunction(); break;
}
return(result);
}
public void TestException()
{
var fn = new InverseSquaredLinkFunction();
double[] x = { 1, 2 };
fn.Evaluate(x);
}
public void TestEvaluate()
{
var fn = new InverseSquaredLinkFunction();
double[] x = { 2 };
double y = fn.Evaluate(x);
Assert.AreEqual(-0.25, y, AIFH.DefaultPrecision);
}
public void InverseSquaredLinkFunctionConstructorTest()
{
InverseSquaredLinkFunction target = new InverseSquaredLinkFunction();
Assert.AreEqual(0, target.A);
Assert.AreEqual(1, target.B);
for (int i = 0; i < 11; i++)
{
double x = i / 10.0;
double y = 1 / (x * x);
Assert.AreEqual(y, target.Function(x), 1e-10);
Assert.AreEqual(x, target.Inverse(y), 1e-10);
}
}
public void InverseSquaredLinkFunctionConstructorTest1()
{
double beta = 3.14;
double constant = 2.91;
InverseSquaredLinkFunction target = new InverseSquaredLinkFunction(beta, constant);
Assert.AreEqual(constant, target.A);
Assert.AreEqual(beta, target.B);
for (int i = 0; i < 11; i++)
{
double x = i / 10.0;
double y = (1 / (x * x) - constant) / beta;
Assert.AreEqual(y, target.Function(x), 1e-10);
Assert.AreEqual(x, target.Inverse(y), 1e-10);
}
}
