| public Transform ( double input ) : double[] | ||
| input | double | The input point to be projected into feature space. |
| return | double[] | |
/// <summary>
/// Projects an input point into feature space.
/// </summary>
///
/// <param name="input">The input point to be projected into feature space.</param>
///
/// <returns>
/// The feature space representation of the given <paramref name="input"/> point.
/// </returns>
///
public double[] Transform(double[] input)
{
switch (degree)
{
case 1:
return(Linear.Transform(input, constant));
case 2:
return(Quadratic.Transform(input, constant));
default:
return(Transform(input, degree, constant));
}
}
public void ExpandReverseDistanceWithConstantTest()
{
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 d = Distance.SquareEuclidean(x, y);
double phi_d = kernel.ReverseDistance(phi_x, phi_y);
Assert.AreEqual(5.48, phi_d, 1e-10);
Assert.AreEqual(5.48, d);
Assert.IsFalse(double.IsNaN(phi_d));
Assert.IsFalse(double.IsNaN(d));
}
public void ExpandReverseDistanceTest()
{
Quadratic kernel = new Quadratic(0);
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 d = Distance.SquareEuclidean(x, y);
double phi_d = kernel.ReverseDistance(phi_x, phi_y);
Assert.AreEqual(phi_d, d);
}
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));
}
public void TransformTest_Quadratic()
{
double[][] data =
{
new double[] { 5.1, 3.5, 1.4, 0.2 },
new double[] { 5.0, 3.6, 1.4, 0.2 },
new double[] { 4.9, 3.0, 1.4, 0.2 },
new double[] { 5.8, 4.0, 1.2, 0.2 },
new double[] { 4.7, 3.2, 1.3, 0.2 },
};
var target = new Polynomial(2);
var quadratic = new Quadratic();
double[][] expected = data.Apply(x => quadratic.Transform(x));
double[][] actual = data.Apply(target.Transform);
Assert.IsTrue(expected.IsEqual(actual, 1e-10));
}
