Class NormalizedKernel

JSAT/src/jsat/distributions/kernels/NormalizedKernel.java:31–137

This provides a wrapper kernel that produces a normalized kernel trick from any input kernel trick. A normalized kernel has a maximum output of 1 when two inputs are the same. @author Edward Raff

 * @author Edward Raff
 */
public class NormalizedKernel implements KernelTrick
{
    private KernelTrick k;

    public NormalizedKernel(KernelTrick source_kernel)
    {
        this.k = source_kernel;
    }

    @Override
    public NormalizedKernel clone()
    {
        return new NormalizedKernel(k.clone());
    }

    @Override
    public double eval(Vec a, Vec b)
    {
        double aa = k.eval(a, a);
        double bb = k.eval(b, b);
        if(aa == 0 || bb == 0)
            return 0;
        else
            return k.eval(a, b)/Math.sqrt(aa*bb);
    }

    @Override
    public List<Parameter> getParameters()
    {
        return k.getParameters();
    }

    @Override
    public Parameter getParameter(String paramName)
    {
        return k.getParameter(paramName);
    }

    @Override
    public boolean supportsAcceleration()
    {
        return k.supportsAcceleration();
    }

    @Override
    public List<Double> getAccelerationCache(List<? extends Vec> trainingSet)
    {
        return k.getAccelerationCache(trainingSet);
    }

    @Override
    public List<Double> getQueryInfo(Vec q)
    {
        return k.getQueryInfo(q);
    }

    @Override
    public void addToCache(Vec newVec, List<Double> cache)