de.lmu.ifi.dbs.elki.distance.distancevalue

Class SubspaceDistance

java.lang.Object

de.lmu.ifi.dbs.elki.distance.distancevalue.AbstractDistance<SubspaceDistance>

de.lmu.ifi.dbs.elki.distance.distancevalue.SubspaceDistance

All Implemented Interfaces:

Distance<SubspaceDistance>, Externalizable, Serializable, Comparable<SubspaceDistance>

public class SubspaceDistance
extends AbstractDistance<SubspaceDistance>

The subspace distance is a special distance that indicates the dissimilarity between subspaces of equal dimensionality. The subspace distance between two points is a pair consisting of the distance between the two subspaces spanned by the strong eigenvectors of the two points and the affine distance between the two subspaces.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private double	affineDistance The affine distance.
static SubspaceDistance	FACTORY The static factory instance
static String	SEPARATOR Indicates a separator.
private static long	serialVersionUID Serial version number.
static Pattern	SUBSPACE_PATTERN The pattern for parsing subspace values
private double	subspaceDistance The subspace distance.

Fields inherited from class de.lmu.ifi.dbs.elki.distance.distancevalue.AbstractDistance

DOUBLE_PATTERN, INFINITY_PATTERN, INTEGER_PATTERN

Constructor Summary

Constructors

Constructor and Description
SubspaceDistance() Empty constructor for serialization purposes.
SubspaceDistance(double subspaceDistance, double affineDistance) Constructs a new SubspaceDistance object consisting of the specified subspace distance and affine distance.

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(SubspaceDistance other) Compares this SubspaceDistance with the given SubspaceDistance wrt the represented subspace distance values.
boolean	equals(Object obj) Returns true if this == o has the value true or o is not null and o is of the same class as this instance and this.compareTo(o) is 0, false otherwise.
int	externalizableSize() Returns the number of Bytes this distance uses if it is written to an external file.
double	getAffineDistance() Returns the value of the affine distance.
Pattern	getPattern() Get the pattern accepted by this distance
double	getSubspaceDistance() Returns the value of the subspace distance.
int	hashCode() Any extending class should implement a proper hashCode method.
SubspaceDistance	infiniteDistance() Provides an infinite distance.
SubspaceDistance	nullDistance() Provides a null distance.
SubspaceDistance	parseString(String val) Provides a measurement suitable to this measurement function based on the given pattern.
void	readExternal(ObjectInput in) Reads the subspace distance value and the affine distance value of this SubspaceDistance from the specified stream.
String	toString() Returns a string representation of this SubspaceDistance.
SubspaceDistance	undefinedDistance() Provides an undefined distance.
void	writeExternal(ObjectOutput out) Writes the subspace distance value and the affine distance value of this SubspaceDistance to the specified stream.

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancevalue.AbstractDistance

isInfiniteDistance, isNullDistance, isUndefinedDistance, requiredInputPattern, testInputPattern

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

FACTORY

public static final SubspaceDistance FACTORY

The static factory instance

serialVersionUID

private static final long serialVersionUID

Serial version number.

See Also:

Constant Field Values

SEPARATOR

public static final String SEPARATOR

Indicates a separator.

See Also:

Constant Field Values

SUBSPACE_PATTERN

public static final Pattern SUBSPACE_PATTERN

The pattern for parsing subspace values

subspaceDistance

private double subspaceDistance

The subspace distance.

affineDistance

private double affineDistance

The affine distance.

Constructor Detail

SubspaceDistance

public SubspaceDistance()

Empty constructor for serialization purposes.

SubspaceDistance

public SubspaceDistance(double subspaceDistance,
                double affineDistance)

Constructs a new SubspaceDistance object consisting of the specified subspace distance and affine distance.

Parameters:

subspaceDistance - the distance between the two subspaces spanned by the strong eigenvectors of the two points

affineDistance - the affine distance between the two subspaces

Method Detail

toString

public String toString()

Returns a string representation of this SubspaceDistance.

Specified by:

toString in interface Distance<SubspaceDistance>

Overrides:

toString in class Object

Returns:

the values of the subspace distance and the affine distance separated by blank

compareTo

public int compareTo(SubspaceDistance other)

Compares this SubspaceDistance with the given SubspaceDistance wrt the represented subspace distance values. If both values are considered to be equal, the values of the affine distances are compared.

Returns:

the value of Double.compare(this.subspaceDistance, other.subspaceDistance) if it is a non zero value, the value of Double.compare(this.affineDistance, other.affineDistance) otherwise

hashCode

public int hashCode()

Description copied from class: AbstractDistance

Any extending class should implement a proper hashCode method.

Specified by:

hashCode in class AbstractDistance<SubspaceDistance>

equals

public boolean equals(Object obj)

Description copied from class: AbstractDistance

Returns true if this == o has the value true or o is not null and o is of the same class as this instance and this.compareTo(o) is 0, false otherwise.

Overrides:

equals in class AbstractDistance<SubspaceDistance>

getSubspaceDistance

public double getSubspaceDistance()

Returns the value of the subspace distance.

Returns:

the value of the subspace distance

getAffineDistance

public double getAffineDistance()

Returns the value of the affine distance.

Returns:

the value of the affine distance

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Writes the subspace distance value and the affine distance value of this SubspaceDistance to the specified stream.

Throws:

IOException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException

Reads the subspace distance value and the affine distance value of this SubspaceDistance from the specified stream.

Throws:

IOException

externalizableSize

public int externalizableSize()

Returns the number of Bytes this distance uses if it is written to an external file.

Returns:

16 (2 * 8 Byte for two double values)

getPattern

public Pattern getPattern()

Description copied from class: AbstractDistance

Get the pattern accepted by this distance

Specified by:

getPattern in class AbstractDistance<SubspaceDistance>

Returns:

Pattern

parseString

public SubspaceDistance parseString(String val)
                             throws IllegalArgumentException

Description copied from interface: Distance

Provides a measurement suitable to this measurement function based on the given pattern.

Parameters:

val - a pattern defining a similarity suitable to this measurement function

Returns:

a measurement suitable to this measurement function based on the given pattern

Throws:

IllegalArgumentException - if the given pattern is not compatible with the requirements of this measurement function

infiniteDistance

public SubspaceDistance infiniteDistance()

Description copied from interface: Distance

Provides an infinite distance.

Returns:

an infinite distance

nullDistance

public SubspaceDistance nullDistance()

Description copied from interface: Distance

Provides a null distance.

Returns:

a null distance

undefinedDistance

public SubspaceDistance undefinedDistance()

Description copied from interface: Distance

Provides an undefined distance.

Returns:

an undefined distance