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SparseGaussian Class

Note: This API is now obsolete.

Sparse Gaussian Kernel.
Inheritance Hierarchy
SystemObject
  Accord.Statistics.KernelsKernelBaseDouble
    Accord.Statistics.KernelsKernelBase
      Accord.Statistics.Kernels.SparseSparseGaussian

Namespace:  Accord.Statistics.Kernels.Sparse
Assembly:  Accord.Statistics (in Accord.Statistics.dll) Version: 3.8.0
Syntax
[SerializableAttribute]
[ObsoleteAttribute("Please use the Gaussian kernel with Sparse<double> instead.")]
public sealed class SparseGaussian : KernelBase, 
	IKernel, IKernel<double[]>, IDistance, IDistance<double[]>, 
	IDistance<double[], double[]>, IReverseDistance
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The SparseGaussian type exposes the following members.

Constructors
  NameDescription
Public methodSparseGaussian
Constructs a new Sparse Gaussian Kernel
Public methodSparseGaussian(Double)
Constructs a new Sparse Gaussian Kernel
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Properties
  NameDescription
Public propertyGamma
Gets or sets the gamma value for the kernel. When setting gamma, sigma gets updated accordingly (gamma = 0.5*/sigma^2).
Public propertySigma
Gets or sets the sigma value for the kernel. When setting sigma, gamma gets updated accordingly (gamma = 0.5*/sigma^2).
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Methods
  NameDescription
Public methodDistance
Computes the distance in input space between two points given in feature space.
(Overrides KernelBaseTInputDistance(TInput, TInput).)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Public methodStatic memberEstimate
Estimate appropriate values for sigma given a data set.
Public methodFunction
Gaussian Kernel function.
(Overrides KernelBaseTInputFunction(TInput, TInput).)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodReverseDistance
Computes the squared distance in input space between two points given in feature space.
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Extension Methods
  NameDescription
Public Extension MethodDistance
Computes the kernel distance for a kernel function even if it doesn't implement the IDistance interface. Can be used to check the proper implementation of the distance function.
(Defined by Tools.)
Public Extension MethodHasMethod
Checks whether an object implements a method with the given name.
(Defined by ExtensionMethods.)
Public Extension MethodIsEqual
Compares two objects for equality, performing an elementwise comparison if the elements are vectors or matrices.
(Defined by Matrix.)
Public Extension MethodTo(Type)Overloaded.
Converts an object into another type, irrespective of whether the conversion can be done at compile time or not. This can be used to convert generic types to numeric types during runtime.
(Defined by ExtensionMethods.)
Public Extension MethodToTOverloaded.
Converts an object into another type, irrespective of whether the conversion can be done at compile time or not. This can be used to convert generic types to numeric types during runtime.
(Defined by ExtensionMethods.)
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Remarks

The Gaussian kernel requires tuning for the proper value of σ. Different approaches to this problem includes the use of brute force (i.e. using a grid-search algorithm) or a gradient ascent optimization.

For an example on how to create a sparse kernel, please see the SparseLinear page.

References:

  • P. F. Evangelista, M. J. Embrechts, and B. K. Szymanski. Some Properties of the Gaussian Kernel for One Class Learning. Available on: http://www.cs.rpi.edu/~szymansk/papers/icann07.pdf

See Also