Class CachedKernel

  • All Implemented Interfaces:
    java.io.Serializable, CapabilitiesHandler, OptionHandler, RevisionHandler
    Direct Known Subclasses:
    PolyKernel, Puk, RBFKernel

    public abstract class CachedKernel
    extends Kernel
    Base class for RBFKernel and PolyKernel that implements a simple LRU. (least-recently-used) cache if the cache size is set to a value > 0. Otherwise it uses a full cache.
    Version:
    $Revision: 4549 $
    Author:
    Eibe Frank (eibe@cs.waikato.ac.nz), Shane Legg (shane@intelligenesis.net) (sparse vector code), Stuart Inglis (stuart@reeltwo.com) (sparse vector code), J. Lindgren (jtlindgr{at}cs.helsinki.fi) (RBF kernel), Steven Hugg (hugg@fasterlight.com) (refactored, LRU cache), Bernhard Pfahringer (bernhard@cs.waikato.ac.nz) (full cache)
    See Also:
    Serialized Form
    • Constructor Detail

      • CachedKernel

        public CachedKernel()
        default constructor - does nothing.
    • Method Detail

      • listOptions

        public java.util.Enumeration listOptions()
        Returns an enumeration describing the available options.
        Specified by:
        listOptions in interface OptionHandler
        Overrides:
        listOptions in class Kernel
        Returns:
        an enumeration of all the available options.
      • setOptions

        public void setOptions​(java.lang.String[] options)
                        throws java.lang.Exception
        Parses a given list of options.

        Specified by:
        setOptions in interface OptionHandler
        Overrides:
        setOptions in class Kernel
        Parameters:
        options - the list of options as an array of strings
        Throws:
        java.lang.Exception - if an option is not supported
      • getOptions

        public java.lang.String[] getOptions()
        Gets the current settings of the Kernel.
        Specified by:
        getOptions in interface OptionHandler
        Overrides:
        getOptions in class Kernel
        Returns:
        an array of strings suitable for passing to setOptions
      • eval

        public double eval​(int id1,
                           int id2,
                           Instance inst1)
                    throws java.lang.Exception
        Implements the abstract function of Kernel using the cache. This method uses the evaluate() method to do the actual dot product.
        Specified by:
        eval in class Kernel
        Parameters:
        id1 - the index of the first instance in the dataset
        id2 - the index of the second instance in the dataset
        inst1 - the instance corresponding to id1 (used if id1 == -1)
        Returns:
        the result of the kernel function
        Throws:
        java.lang.Exception - if something goes wrong
      • numEvals

        public int numEvals()
        Returns the number of time Eval has been called.
        Specified by:
        numEvals in class Kernel
        Returns:
        the number of kernel evaluation.
      • numCacheHits

        public int numCacheHits()
        Returns the number of cache hits on dot products.
        Specified by:
        numCacheHits in class Kernel
        Returns:
        the number of cache hits.
      • clean

        public void clean()
        Frees the cache used by the kernel.
        Specified by:
        clean in class Kernel
      • setCacheSize

        public void setCacheSize​(int value)
        Sets the size of the cache to use (a prime number)
        Parameters:
        value - the size of the cache
      • getCacheSize

        public int getCacheSize()
        Gets the size of the cache
        Returns:
        the cache size
      • cacheSizeTipText

        public java.lang.String cacheSizeTipText()
        Returns the tip text for this property
        Returns:
        tip text for this property suitable for displaying in the explorer/experimenter gui
      • buildKernel

        public void buildKernel​(Instances data)
                         throws java.lang.Exception
        builds the kernel with the given data. Initializes the kernel cache. The actual size of the cache in bytes is (64 * cacheSize).
        Overrides:
        buildKernel in class Kernel
        Parameters:
        data - the data to base the kernel on
        Throws:
        java.lang.Exception - if something goes wrong