de.lmu.ifi.dbs.elki.preprocessing
Class HiSCPreprocessor<V extends NumberVector<V,?>>

java.lang.Object
  de.lmu.ifi.dbs.elki.logging.AbstractLoggable
      de.lmu.ifi.dbs.elki.preprocessing.HiSCPreprocessor<V>

Type Parameters:

V - the type of NumberVector handled by the preprocessor

All Implemented Interfaces:

PreferenceVectorPreprocessor<V>, Preprocessor<V>, Parameterizable

@Title(value="HiSC Preprocessor")
@Description(value="Computes the preference vector of objects of a certain database according to the HiSC algorithm.")
public class HiSCPreprocessor<V extends NumberVector<V,?>>
extends AbstractLoggable
implements PreferenceVectorPreprocessor<V>, Parameterizable

Preprocessor for HiSC preference vector assignment to objects of a certain database.

Author:

Elke Achtert

See Also:

HiSC

Field Summary

private double	alpha Holds the value of parameter ALPHA_PARAM.
static OptionID	ALPHA_ID OptionID for ALPHA_PARAM
private DoubleParameter	ALPHA_PARAM The maximum absolute variance along a coordinate axis.
static double	DEFAULT_ALPHA The default value for alpha.
private Integer	k Holds the value of parameter K_PARAM.
static OptionID	K_ID OptionID for K_PARAM.
private IntParameter	K_PARAM The number of nearest neighbors considered to determine the preference vector.

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

debug, logger

Constructor Summary

HiSCPreprocessor(Parameterization config)
Constructor, adhering to Parameterizable

Method Summary

private BitSet	determinePreferenceVector(Database<V> database, Integer id, List<Integer> neighborIDs, StringBuffer msg) Determines the preference vector according to the specified neighbor ids.
double	getAlpha() Returns the value of the alpha parameter (i.e. the maximum allowed variance along a coordinate axis).
int	getK() Returns the value of the k parameter (i.e. the number of nearest neighbors considered to determine the preference vector).
void	run(Database<V> database, boolean verbose, boolean time) This method executes the particular preprocessing step of this Preprocessor for the objects of the specified database.

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

DEFAULT_ALPHA

public static final double DEFAULT_ALPHA

The default value for alpha.

See Also:

Constant Field Values

ALPHA_ID

public static final OptionID ALPHA_ID

OptionID for ALPHA_PARAM

ALPHA_PARAM

private final DoubleParameter ALPHA_PARAM

The maximum absolute variance along a coordinate axis. Must be in the range of [0.0, 1.0).

Default value: DEFAULT_ALPHA

Key: -hisc.alpha

alpha

private double alpha

Holds the value of parameter ALPHA_PARAM.

K_ID

public static final OptionID K_ID

OptionID for K_PARAM.

K_PARAM

private final IntParameter K_PARAM

The number of nearest neighbors considered to determine the preference vector. If this value is not defined, k is set to three times of the dimensionality of the database objects.

Key: -hisc.k

Default value: three times of the dimensionality of the database objects

k

private Integer k

Holds the value of parameter K_PARAM.

Constructor Detail

HiSCPreprocessor

public HiSCPreprocessor(Parameterization config)

Constructor, adhering to Parameterizable

Parameters:

config - Parameterization

Method Detail

run

public void run(Database<V> database,
                boolean verbose,
                boolean time)

Description copied from interface: Preprocessor

This method executes the particular preprocessing step of this Preprocessor for the objects of the specified database.

Specified by:

run in interface Preprocessor<V extends NumberVector<V,?>>

Parameters:

database - the database for which the preprocessing is performed

verbose - flag to allow verbose messages while performing the algorithm

time - flag to request output of performance time

getAlpha

public double getAlpha()

Returns the value of the alpha parameter (i.e. the maximum allowed variance along a coordinate axis).

Returns:

the value of the alpha parameter

getK

public int getK()

Returns the value of the k parameter (i.e. the number of nearest neighbors considered to determine the preference vector).

Returns:

the value of the k parameter

determinePreferenceVector

private BitSet determinePreferenceVector(Database<V> database,
                                         Integer id,
                                         List<Integer> neighborIDs,
                                         StringBuffer msg)

Determines the preference vector according to the specified neighbor ids.

Parameters:

database - the database storing the objects

id - the id of the object for which the preference vector should be determined

neighborIDs - the ids of the neighbors

msg - a string buffer for debug messages

Returns:

the preference vector