smile.math.kernel

Class LaplacianKernel

java.lang.Object

smile.math.kernel.Laplacian

smile.math.kernel.LaplacianKernel

All Implemented Interfaces:

java.io.Serializable, java.util.function.ToDoubleBiFunction<double[],double[]>, Function, IsotropicKernel, MercerKernel<double[]>

public class LaplacianKernel
extends Laplacian
implements MercerKernel<double[]>

Laplacian kernel, also referred as exponential kernel.

     k(u, v) = e-||u-v|| / σ
 

where σ > 0 is the scale parameter of the kernel.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LaplacianKernel(double sigma) Constructor.
LaplacianKernel(double sigma, double lo, double hi) Constructor.

Method Summary

Modifier and Type	Method and Description
double[]	hi() Returns the upper bound of hyperparameters.
double[]	hyperparameters() Returns the hyperparameters for tuning.
double	k(double[] x, double[] y) Kernel function.
double[]	kg(double[] x, double[] y) Computes the kernel and its gradient over hyperparameters.
double[]	lo() Returns the lower bound of hyperparameters.
LaplacianKernel	of(double[] params) Returns the same kind kernel with the new hyperparameters.

Methods inherited from class smile.math.kernel.Laplacian

k, kg, scale, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface smile.math.kernel.MercerKernel

apply, applyAsDouble, K, K, KG

Methods inherited from interface smile.math.kernel.IsotropicKernel

apply, f, K, KG

Constructor Detail

LaplacianKernel

public LaplacianKernel(double sigma)

Constructor.

Parameters:

sigma - The length scale of kernel.

LaplacianKernel

public LaplacianKernel(double sigma,
                       double lo,
                       double hi)

Constructor.

Parameters:

sigma - The length scale of kernel.

lo - The lower bound of length scale for hyperparameter tuning.

hi - The upper bound of length scale for hyperparameter tuning.

Method Detail

k

public double k(double[] x,
                double[] y)

Description copied from interface: MercerKernel

Kernel function.

Specified by:

k in interface MercerKernel<double[]>

kg

public double[] kg(double[] x,
                   double[] y)

Description copied from interface: MercerKernel

Computes the kernel and its gradient over hyperparameters.

Specified by:

kg in interface MercerKernel<double[]>

of

public LaplacianKernel of(double[] params)

Description copied from interface: MercerKernel

Returns the same kind kernel with the new hyperparameters.

Specified by:

of in interface MercerKernel<double[]>

hyperparameters

public double[] hyperparameters()

Description copied from interface: MercerKernel

Returns the hyperparameters for tuning.

Specified by:

hyperparameters in interface MercerKernel<double[]>

lo

public double[] lo()

Description copied from interface: MercerKernel

Returns the lower bound of hyperparameters.

Specified by:

lo in interface MercerKernel<double[]>

hi

public double[] hi()

Description copied from interface: MercerKernel

Returns the upper bound of hyperparameters.

Specified by:

hi in interface MercerKernel<double[]>