public void ExpandDistanceWithConstantTest()
{
Quadratic kernel = new Quadratic(4.2);
var x = new double[] { 0.5, 2.0 };
var y = new double[] { 1.3, -0.2 };
var phi_x = kernel.Transform(x);
var phi_y = kernel.Transform(y);
double d1 = Distance.SquareEuclidean(phi_x, phi_y);
double d2 = kernel.Distance(x, y);
double d3 = Accord.Statistics.Tools.Distance(kernel, x, y);
Assert.AreEqual(66.9624, d1);
Assert.AreEqual(66.9624, d2, 1e-10);
Assert.AreEqual(66.9624, d3, 1e-10);
Assert.IsFalse(double.IsNaN(d1));
Assert.IsFalse(double.IsNaN(d2));
Assert.IsFalse(double.IsNaN(d3));
}