de.lmu.ifi.dbs.elki.utilities.scaling.outlier
Class MultiplicativeInverseScaling

java.lang.Object
  de.lmu.ifi.dbs.elki.utilities.scaling.outlier.MultiplicativeInverseScaling

All Implemented Interfaces:

InspectionUtilFrequentlyScanned, Parameterizable, OutlierScalingFunction, ScalingFunction

@Reference(authors="H.-P. Kriegel, P. Kr\u00f6ger, E. Schubert, A. Zimek",
           title="Interpreting and Unifying Outlier Scores",
           booktitle="Proc. 11th SIAM International Conference on Data Mining (SDM), Mesa, AZ, 2011",
           url="http://www.dbs.ifi.lmu.de/~zimek/publications/SDM2011/SDM11-outlier-preprint.pdf")
public class MultiplicativeInverseScaling
extends Object
implements OutlierScalingFunction

Scaling function to invert values basically by computing 1/x, but in a variation that maps the values to the [0:1] interval and avoiding division by 0. The exact formula can be written as 1 / (value * max_{x!=0}(1 / abs(x))) = min_{x != 0}(abs(x)) / x with 1 / 0 := 1

Field Summary

(package private) double

scaleval Scaling value, set by prepare(de.lmu.ifi.dbs.elki.result.outlier.OutlierResult).

Constructor Summary

MultiplicativeInverseScaling()
Constructor, adhering to Parameterizable

Method Summary

double	getMax() Get maximum resulting value.
double	getMin() Get minimum resulting value.
double	getScaled(double value) Transform a given value using the scaling function.
private static double	getScaleValue(OutlierResult or) Compute the scaling value in a linear scan over the annotation.
void	prepare(OutlierResult or) Prepare is called once for each data set, before getScaled() will be called.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

scaleval

double scaleval

Scaling value, set by prepare(de.lmu.ifi.dbs.elki.result.outlier.OutlierResult).

Constructor Detail

MultiplicativeInverseScaling

public MultiplicativeInverseScaling()

Constructor, adhering to Parameterizable

Method Detail

getScaled

public double getScaled(double value)

Description copied from interface: ScalingFunction

Transform a given value using the scaling function.

Specified by:

getScaled in interface ScalingFunction

Parameters:

value - Original value

Returns:

Scaled value

prepare

public void prepare(OutlierResult or)

Description copied from interface: OutlierScalingFunction

Prepare is called once for each data set, before getScaled() will be called. This function can be used to extract global parameters such as means, minimums or maximums from the Database, Result or Annotation.

Specified by:

prepare in interface OutlierScalingFunction

Parameters:

or - Outlier result to use

getScaleValue

private static double getScaleValue(OutlierResult or)

Compute the scaling value in a linear scan over the annotation.

Parameters:

or - Outlier result

Returns:

Scaling value.

getMin

public double getMin()

Description copied from interface: ScalingFunction

Get minimum resulting value. May be Double.NaN or Double.NEGATIVE_INFINITY.

Specified by:

getMin in interface ScalingFunction

Returns:

Minimum resulting value.

getMax

public double getMax()

Description copied from interface: ScalingFunction

Get maximum resulting value. May be Double.NaN or Double.POSITIVE_INFINITY.

Specified by:

getMax in interface ScalingFunction

Returns:

Maximum resulting value.