Environment for
DeveLoping
KDD-Applications
Supported by Index-Structures

de.lmu.ifi.dbs.elki.distance.distancefunction
Class SquareRootSupportLengthDependentItemsetDistanceFunction

java.lang.Object
  extended by de.lmu.ifi.dbs.elki.logging.AbstractLoggable
      extended by de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizable
          extended by de.lmu.ifi.dbs.elki.distance.AbstractMeasurementFunction<O,D>
              extended by de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDistanceFunction<O,DoubleDistance>
                  extended by de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDoubleDistanceFunction<BitVector>
                      extended by de.lmu.ifi.dbs.elki.distance.distancefunction.SharingDependentItemsetDistanceFunction
                          extended by de.lmu.ifi.dbs.elki.distance.distancefunction.FrequencyDependentItemsetDistanceFunction
                              extended by de.lmu.ifi.dbs.elki.distance.distancefunction.SquareRootSupportLengthDependentItemsetDistanceFunction
All Implemented Interfaces:
DistanceFunction<BitVector,DoubleDistance>, MeasurementFunction<BitVector,DoubleDistance>, Loggable, Parameterizable

public class SquareRootSupportLengthDependentItemsetDistanceFunction
extends FrequencyDependentItemsetDistanceFunction

Provides a DistanceFunction to compute a Distance between BitVectors based on the number of shared bits.

Author:
Arthur Zimek

Field Summary
 
Fields inherited from class de.lmu.ifi.dbs.elki.distance.AbstractMeasurementFunction
INFINITY_PATTERN
 
Fields inherited from class de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizable
optionHandler
 
Fields inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable
debug
 
Constructor Summary
SquareRootSupportLengthDependentItemsetDistanceFunction()
          Provides a DistanceFunction to compute a Distance between BitVectors based on the number of shared bits.
 
Method Summary
 String description()
          Returns a description of the class and the required parameters.
 DoubleDistance distance(BitVector o1, BitVector o2)
          Returns a distance between two Bitvectors.
 
Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.FrequencyDependentItemsetDistanceFunction
setDatabase, support
 
Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.SharingDependentItemsetDistanceFunction
ratio
 
Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDoubleDistanceFunction
infiniteDistance, nullDistance, undefinedDistance, valueOf
 
Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDistanceFunction
distance, distance, isInfiniteDistance, isNullDistance, isUndefinedDistance
 
Methods inherited from class de.lmu.ifi.dbs.elki.distance.AbstractMeasurementFunction
getDatabase, matches, requiredInputPattern, setRequiredInputPattern
 
Methods inherited from class de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizable
addOption, checkGlobalParameterConstraints, deleteOption, description, description, getAttributeSettings, getParameters, getParameterValue, getPossibleOptions, inlineDescription, isSet, setParameters, setParameters
 
Methods inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable
debugFine, debugFiner, debugFinest, exception, message, progress, progress, progress, verbose, verbose, warning
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface de.lmu.ifi.dbs.elki.distance.MeasurementFunction
requiredInputPattern
 
Methods inherited from interface de.lmu.ifi.dbs.elki.utilities.optionhandling.Parameterizable
checkGlobalParameterConstraints, getAttributeSettings, getParameters, getPossibleOptions, inlineDescription, setParameters
 

Constructor Detail

SquareRootSupportLengthDependentItemsetDistanceFunction

public SquareRootSupportLengthDependentItemsetDistanceFunction()
Provides a DistanceFunction to compute a Distance between BitVectors based on the number of shared bits.

Method Detail

distance

public DoubleDistance distance(BitVector o1,
                               BitVector o2)
Returns a distance between two Bitvectors. Distance is (sqrt(1.0 / support(%)) * (1.0 / (i==0 ? 1 : i))) * max{1-ratio(i,card1),1-ratio(i,card2)}, where i is the number of bits shared by both BitVectors, o is the number of bits in the respective BitVector, and ratio(i,card) is 1 if card is 0, i/card otherwise.

Parameters:
o1 - first BitVector
o2 - second BitVector
Returns:
Distance between o1 and o2

description

public String description()
Description copied from interface: Parameterizable
Returns a description of the class and the required parameters.

This description should be suitable for a usage description as for a standalone application.

Specified by:
description in interface Parameterizable
Overrides:
description in class AbstractParameterizable
Returns:
String a description of the class and the required parameters
See Also:
Parameterizable.description()

Release 0.1 (2008-07-10_1838)