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

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

public final class GaussStddevWeight
extends Object
implements WeightFunction

Gaussian Weight function, scaled such using standard deviation factor * exp(-.5 * (distance/stddev)^2) with factor being 1 / sqrt(2 * PI)


Field Summary
private static double scaling
          Constant scaling factor of Gaussian distribution.
 
Constructor Summary
GaussStddevWeight()
           
 
Method Summary
 double getWeight(double distance, double max, double stddev)
          Get Gaussian Weight using standard deviation for scaling. max is ignored.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

scaling

private static final double scaling
Constant scaling factor of Gaussian distribution. In fact, in most use cases we could leave this away.

Constructor Detail

GaussStddevWeight

public GaussStddevWeight()
Method Detail

getWeight

public double getWeight(double distance,
                        double max,
                        double stddev)
Get Gaussian Weight using standard deviation for scaling. max is ignored.

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 0.4.0 (2011-09-20_1324)