KernelMatrix 
Kernel matrix representation.

KernelMatrix.DBIDMap 
Map a DBID to its offset
TODO: move to shared code.

LaplaceKernel 
Laplace / exponential radial basis function kernel.

LinearKernel 
Linear Kernel function that computes a similarity between the two feature
vectors x and y defined by \(x^T\cdot y\).

PolynomialKernel 
Polynomial Kernel function that computes a similarity between the two feature
vectors x and y defined by \((x^T\cdot y+b)^{\text{degree}}\).

RadialBasisFunctionKernel 
Gaussian radial basis function kernel (RBF Kernel).

RationalQuadraticKernel 

SigmoidKernel 
Sigmoid kernel function (aka: hyperbolic tangent kernel, multilayer
perceptron MLP kernel).
