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

java.lang.Object
  de.lmu.ifi.dbs.elki.logging.AbstractLoggable
      de.lmu.ifi.dbs.elki.utilities.scaling.outlier.StandardDeviationScaling

All Implemented Interfaces:

Parameterizable, OutlierScalingFunction, ScalingFunction

Direct Known Subclasses:

MinusLogStandardDeviationScaling

public class StandardDeviationScaling
extends AbstractLoggable
implements OutlierScalingFunction

Scaling that can map arbitrary values to a probability in the range of [0:1]. Transformation is done using the formula max(0, erf(lambda * (x - mean) / (stddev * sqrt(2)))) Where mean can be fixed to a given value, and stddev is then computed against this mean.

Author:

Erich Schubert

Field Summary

(package private) double	factor Scaling factor to use (usually: Lambda * Stddev * Sqrt(2))
protected Double	fixedmean Field storing the fixed mean to use
protected Double	lambda Field storing the lambda value
static OptionID	LAMBDA_ID OptionID for LAMBDA_PARAM
private DoubleParameter	LAMBDA_PARAM Parameter to specify the lambda value Key: -stddevscale.lambda
(package private) double	mean Mean to use
static OptionID	MEAN_ID OptionID for MEAN_PARAM
private DoubleParameter	MEAN_PARAM Parameter to specify a fixed mean to use.

Fields inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable

debug, logger

Constructor Summary

StandardDeviationScaling(Parameterization config)
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.
void	prepare(Database<?> db, Result result, OutlierResult or) Prepare is called once for each data set, before getScaled() will be called.

Methods inherited from class de.lmu.ifi.dbs.elki.logging.AbstractLoggable

debugFine, debugFiner, debugFinest, exception, progress, verbose, warning

Methods inherited from class java.lang.Object

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

Field Detail

MEAN_ID

public static final OptionID MEAN_ID

OptionID for MEAN_PARAM

MEAN_PARAM

private final DoubleParameter MEAN_PARAM

Parameter to specify a fixed mean to use.

Key: -stddevscale.mean

LAMBDA_ID

public static final OptionID LAMBDA_ID

OptionID for LAMBDA_PARAM

LAMBDA_PARAM

private final DoubleParameter LAMBDA_PARAM

Parameter to specify the lambda value

Key: -stddevscale.lambda

fixedmean

protected Double fixedmean

Field storing the fixed mean to use

lambda

protected Double lambda

Field storing the lambda value

mean

double mean

Mean to use

factor

double factor

Scaling factor to use (usually: Lambda * Stddev * Sqrt(2))

Constructor Detail

StandardDeviationScaling

public StandardDeviationScaling(Parameterization config)

Constructor, adhering to Parameterizable

Parameters:

config - Parameterization

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(Database<?> db,
                    Result result,
                    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:

db - Database used

result - Result object

or - Outlier result to use

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.