smile.math.kernel

Class Polynomial

java.lang.Object

smile.math.kernel.Polynomial

All Implemented Interfaces:

java.io.Serializable, Function, DotProductKernel

Direct Known Subclasses:

BinarySparsePolynomialKernel, PolynomialKernel, SparsePolynomialKernel

public class Polynomial
extends java.lang.Object
implements DotProductKernel

The polynomial kernel.

     k(u, v) = (γ uTv - λ)d
 

where γ is the scale of the used inner product, λ the offset of the used inner product, and d the order of the polynomial kernel.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Polynomial(int degree, double scale, double offset, double[] lo, double[] hi) Constructor.

Method Summary

Modifier and Type	Method and Description
int	degree() Returns the degree of kernel.
double	k(double dot) Computes the dot product kernel function.
double[]	kg(double dot) Computes the dot product kernel function and its gradient over hyperparameters..
double	offset() Returns the offset of kernel.
double	scale() Returns the scale of kernel.
java.lang.String	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.DotProductKernel

apply, f, K

Constructor Detail

Polynomial

public Polynomial(int degree,
                  double scale,
                  double offset,
                  double[] lo,
                  double[] hi)

Constructor.

Parameters:

degree - The degree of polynomial. The degree is fixed during hyperparameter tuning.

scale - The scale parameter.

offset - The offset parameter.

lo - The lower bound of scale and offset for hyperparameter tuning.

hi - The upper bound of scale and offset for hyperparameter tuning.

Method Detail

degree

public int degree()

Returns the degree of kernel.

scale

public double scale()

Returns the scale of kernel.

offset

public double offset()

Returns the offset of kernel.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

k

public double k(double dot)

Description copied from interface: DotProductKernel

Computes the dot product kernel function.

Specified by:

k in interface DotProductKernel

Parameters:

dot - the dot product.

kg

public double[] kg(double dot)

Description copied from interface: DotProductKernel

Computes the dot product kernel function and its gradient over hyperparameters..

Specified by:

kg in interface DotProductKernel

Parameters:

dot - The dot product.