Package elki.math.linearalgebra.pca.weightfunctions

Class ExponentialWeight

  • All Implemented Interfaces:
    WeightFunction
    public final class ExponentialWeight
extends java.lang.Object
implements WeightFunction
    Exponential Weight function, scaled such that the result it 0.1 at distance equal max, so it does not completely disappear using: \( \exp(-2.3025850929940455 \frac{\text{distance}}{\max}) \)

    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 to 0.1

    Since:
    0.2
    Author:
    Erich Schubert

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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