Package elki.distance.external

Class DiskCacheBasedDoubleDistance

java.lang.Object

elki.distance.AbstractDatabaseDistance<DBID>

elki.distance.AbstractDBIDRangeDistance

elki.distance.external.DiskCacheBasedDoubleDistance

All Implemented Interfaces:

DBIDDistance, DBIDRangeDistance, Distance<DBID>

public class DiskCacheBasedDoubleDistance
extends AbstractDBIDRangeDistance

Distance function that is based on double distances given by a distance matrix of an external binary matrix file.

Since:

0.2

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DiskCacheBasedDoubleDistance.Par	Parameterization class.

Nested classes/interfaces inherited from class elki.distance.AbstractDatabaseDistance

AbstractDatabaseDistance.Instance<O>

Field Summary

Fields

Modifier and Type	Field	Description
private OnDiskUpperTriangleMatrix	cache	The distance matrix
static int	DOUBLE_CACHE_MAGIC	Magic to identify double cache matrices
private static Logging	LOG	Class logger.

Constructor Summary

Constructors

Constructor	Description
DiskCacheBasedDoubleDistance(OnDiskUpperTriangleMatrix cache)	Constructor.
DiskCacheBasedDoubleDistance(java.nio.file.Path matrixfile)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	checkRange(DBIDRange range)	Validate the range of DBIDs to use.
double	distance(int i1, int i2)	Compute the distance for two integer offsets.
boolean	equals(java.lang.Object obj)

Methods inherited from class elki.distance.AbstractDBIDRangeDistance

distance, getInputTypeRestriction, instantiate

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.distance.Distance

isMetric, isSquared, isSymmetric

Field Detail

LOG

private static final Logging LOG

Class logger.

DOUBLE_CACHE_MAGIC

public static final int DOUBLE_CACHE_MAGIC

Magic to identify double cache matrices

See Also:

Constant Field Values

cache

private OnDiskUpperTriangleMatrix cache

The distance matrix

Constructor Detail

DiskCacheBasedDoubleDistance

public DiskCacheBasedDoubleDistance(OnDiskUpperTriangleMatrix cache)

Constructor.

Parameters:

cache - Distance matrix

DiskCacheBasedDoubleDistance

public DiskCacheBasedDoubleDistance(java.nio.file.Path matrixfile)
                             throws java.io.IOException

Constructor.

Parameters:

matrixfile - File name

Throws:

java.io.IOException

Method Detail

distance

public double distance(int i1,
                       int i2)

Description copied from interface: DBIDRangeDistance

Compute the distance for two integer offsets.

Parameters:

i1 - First offset

i2 - Second offset

Returns:

Distance

checkRange

public void checkRange(DBIDRange range)

Description copied from interface: DBIDRangeDistance

Validate the range of DBIDs to use. This will log a warning if an obvious mismatch was found.

Parameters:

range - DBID range

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object