Environment for
DeveLoping
KDD-Applications
Supported by Index-Structures

de.lmu.ifi.dbs.elki.math.linearalgebra.pca.weightfunctions
Class ExponentialWeight

java.lang.Object
  extended by de.lmu.ifi.dbs.elki.math.linearalgebra.pca.weightfunctions.ExponentialWeight
All Implemented Interfaces:
WeightFunction

public final class ExponentialWeight
extends Object
implements WeightFunction

Exponential Weight function, scaled such that the result it 0.1 at distance == max exp(-2.3025850929940455 * distance/max) This is similar to the Gaussian weight function, except distance/max is not squared. -2.3025850929940455 is log(-.1) to achieve the intended range of 1.0 - 0.1

Author:
Erich Schubert

Constructor Summary
ExponentialWeight()
           
 
Method Summary
 double getWeight(double distance, double max, double stddev)
          Exponential Weight function. stddev is not used.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ExponentialWeight

public ExponentialWeight()
Method Detail

getWeight

public double getWeight(double distance,
                        double max,
                        double stddev)
Exponential Weight function. stddev is not used.

Specified by:
getWeight in interface WeightFunction
Parameters:
distance - distance of the query point
max - maximum distance of all included points
stddev - standard deviation (i.e. quadratic mean / RMS) of the included points
Returns:
weight for the query point

Release 0.2.1 (2009-07-13_1605)