Package weka.core

Class FilteredDistance

  • All Implemented Interfaces:
    java.io.Serializable, DistanceFunction, OptionHandler
    public class FilteredDistance
extends java.lang.Object
implements DistanceFunction, OptionHandler, java.io.Serializable
    Applies the given filter before calling the given distance function.

    Valid options are: 

     -F
  The filter to use. (default: weka.unsupervised.attribute.RandomProjection
     -E
  The distance function to use. (default: weka.core.EuclideanDistance
     
 Options specific to filter weka.filters.unsupervised.attribute.RandomProjection:
 
     -N <number>
  The number of dimensions (attributes) the data should be reduced to
  (default 10; exclusive of the class attribute, if it is set).
     -D [SPARSE1|SPARSE2|GAUSSIAN]
  The distribution to use for calculating the random matrix.
  Sparse1 is:
    sqrt(3)*{-1 with prob(1/6), 0 with prob(2/3), +1 with prob(1/6)}
  Sparse2 is:
    {-1 with prob(1/2), +1 with prob(1/2)}
 
     -P <percent>
  The percentage of dimensions (attributes) the data should
  be reduced to (exclusive of the class attribute, if it is set). The -N
  option is ignored if this option is present and is greater
  than zero.
     -M
  Replace missing values using the ReplaceMissingValues filter
     -R <num>
  The random seed for the random number generator used for
  calculating the random matrix (default 42).
     
 Options specific to distance function weka.core.EuclideanDistance:
 
     -D
  Turns off the normalization of attribute 
  values in distance calculation.
     -R <col1,col2-col4,...>
  Specifies list of columns to used in the calculation of the 
  distance. 'first' and 'last' are valid indices.
  (default: first-last)
     -V
  Invert matching sense of column indices.
     -R <col1,col2-col4,...>
  Specifies list of columns to used in the calculation of the 
  distance. 'first' and 'last' are valid indices.
  (default: first-last)
     -V
  Invert matching sense of column indices.
    Version:
    $Revision: 8034 $
    Author:
    Eibe Frank (eibe@cs.waikato.ac.nz)
    See Also:
    Serialized Form

    • Constructor Detail

      • FilteredDistance

        public FilteredDistance()
        Default constructor: need to set up Remove filter.

    • Method Detail

      • globalInfo

        public java.lang.String globalInfo()
        Returns a string describing this object.
        Returns:
        a description of the evaluator suitable for displaying in the explorer/experimenter gui

      • filterTipText

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

      • setFilter

        public void setFilter​(Filter filter)
        Sets the filter
        Parameters:
        filter - the filter with all options set.

      • getFilter

        public Filter getFilter()
        Gets the filter used.
        Returns:
        the filter

      • distanceTipText

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

      • setDistance

        public void setDistance​(DistanceFunction distance)
        Sets the distance
        Parameters:
        distance - the distance with all options set.

      • getDistance

        public DistanceFunction getDistance()
        Gets the distance used.
        Returns:
        the distance

      • listOptions

        public java.util.Enumeration<Option> listOptions()
        Returns an enumeration describing the available options.
        Specified by:
        listOptions in interface OptionHandler
        Returns:
        an enumeration of all the available options.

      • getOptions

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

      • setOptions

        public void setOptions​(java.lang.String[] options)
                throws java.lang.Exception
        Parses a given list of options.
        Specified by:
        setOptions in interface OptionHandler
        Parameters:
        options - the list of options as an array of strings
        Throws:
        java.lang.Exception - if an option is not supported

      • setAttributeIndices

        public void setAttributeIndices​(java.lang.String value)
        Sets the range of attributes to use in the calculation of the distance. The indices start from 1, 'first' and 'last' are valid as well. E.g.: first-3,5,6-last
        Specified by:
        setAttributeIndices in interface DistanceFunction
        Parameters:
        value - the new attribute index range

      • getAttributeIndices

        public java.lang.String getAttributeIndices()
        Gets the range of attributes used in the calculation of the distance.
        Specified by:
        getAttributeIndices in interface DistanceFunction
        Returns:
        the attribute index range

      • setInvertSelection

        public void setInvertSelection​(boolean value)
        Sets whether the matching sense of attribute indices is inverted or not.
        Specified by:
        setInvertSelection in interface DistanceFunction
        Parameters:
        value - if true the matching sense is inverted

      • getInvertSelection

        public boolean getInvertSelection()
        Gets whether the matching sense of attribute indices is inverted or not.
        Specified by:
        getInvertSelection in interface DistanceFunction
        Returns:
        true if the matching sense is inverted

      • distance

        public double distance​(Instance first,
                       Instance second)
        Calculates the distance between two instances.
        Specified by:
        distance in interface DistanceFunction
        Parameters:
        first - the first instance
        second - the second instance
        Returns:
        the distance between the two given instances

      • distance

        public double distance​(Instance first,
                       Instance second,
                       PerformanceStats stats)
                throws java.lang.Exception
        Calculates the distance between two instances.
        Specified by:
        distance in interface DistanceFunction
        Parameters:
        first - the first instance
        second - the second instance
        stats - the performance stats object
        Returns:
        the distance between the two given instances
        Throws:
        java.lang.Exception - if calculation fails

      • distance

        public double distance​(Instance first,
                       Instance second,
                       double cutOffValue)
        Calculates the distance between two instances. Offers speed up (if the distance function class in use supports it) in nearest neighbour search by taking into account the cutOff or maximum distance. Depending on the distance function class, post processing of the distances by postProcessDistances(double []) may be required if this function is used.
        Specified by:
        distance in interface DistanceFunction
        Parameters:
        first - the first instance
        second - the second instance
        cutOffValue - If the distance being calculated becomes larger than cutOffValue then the rest of the calculation is discarded.
        Returns:
        the distance between the two given instances or Double.POSITIVE_INFINITY if the distance being calculated becomes larger than cutOffValue.

      • distance

        public double distance​(Instance first,
                       Instance second,
                       double cutOffValue,
                       PerformanceStats stats)
        Calculates the distance between two instances. Offers speed up (if the distance function class in use supports it) in nearest neighbour search by taking into account the cutOff or maximum distance. Depending on the distance function class, post processing of the distances by postProcessDistances(double []) may be required if this function is used.
        Specified by:
        distance in interface DistanceFunction
        Parameters:
        first - the first instance
        second - the second instance
        cutOffValue - If the distance being calculated becomes larger than cutOffValue then the rest of the calculation is discarded.
        stats - the performance stats object
        Returns:
        the distance between the two given instances or Double.POSITIVE_INFINITY if the distance being calculated becomes larger than cutOffValue.

      • postProcessDistances

        public void postProcessDistances​(double[] distances)
        Does post processing of the distances (if necessary) returned by distance(distance(Instance first, Instance second, double cutOffValue). It may be necessary, depending on the distance function, to do post processing to set the distances on the correct scale. Some distance function classes may not return correct distances using the cutOffValue distance function to minimize the inaccuracies resulting from floating point comparison and manipulation.
        Specified by:
        postProcessDistances in interface DistanceFunction
        Parameters:
        distances - the distances to post-process

      • update

        public void update​(Instance ins)
        Update the distance function (if necessary) for the newly added instance.
        Specified by:
        update in interface DistanceFunction
        Parameters:
        ins - the instance to add

      • clean

        public void clean()
        Free any references to training instances
        Specified by:
        clean in interface DistanceFunction