de.lmu.ifi.dbs.elki.distance.distancefunction.external

Class DiskCacheBasedFloatDistanceFunction

java.lang.Object

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDatabaseDistanceFunction<DBID>

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDBIDRangeDistanceFunction

de.lmu.ifi.dbs.elki.distance.distancefunction.external.DiskCacheBasedFloatDistanceFunction

All Implemented Interfaces:

DBIDDistanceFunction, DBIDRangeDistanceFunction, DistanceFunction<DBID>

public class DiskCacheBasedFloatDistanceFunction
extends AbstractDBIDRangeDistanceFunction

Distance function that is based on float 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 and Description
static class	DiskCacheBasedFloatDistanceFunction.Parameterizer Parameterization class.

Nested classes/interfaces inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDatabaseDistanceFunction

AbstractDatabaseDistanceFunction.Instance<O>

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
DiskCacheBasedFloatDistanceFunction(java.io.File matrixfile) Constructor.
DiskCacheBasedFloatDistanceFunction(OnDiskUpperTriangleMatrix cache) Constructor.

Method Summary

Modifier and Type	Method and 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 de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDBIDRangeDistanceFunction

distance, getInputTypeRestriction, instantiate

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractDatabaseDistanceFunction

isMetric, isSymmetric

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.distance.distancefunction.DistanceFunction

isMetric, isSquared, isSymmetric

Field Detail

LOG

private static final Logging LOG

Class logger.

FLOAT_CACHE_MAGIC

public static final int FLOAT_CACHE_MAGIC

Magic to identify double cache matrices

See Also:

Constant Field Values

cache

private OnDiskUpperTriangleMatrix cache

The distance cache

Constructor Detail

DiskCacheBasedFloatDistanceFunction

public DiskCacheBasedFloatDistanceFunction(OnDiskUpperTriangleMatrix cache)

Constructor.

Parameters:

cache - Distance matrix

DiskCacheBasedFloatDistanceFunction

public DiskCacheBasedFloatDistanceFunction(java.io.File 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: DBIDRangeDistanceFunction

Compute the distance for two integer offsets.

Parameters:

i1 - First offset

i2 - Second offset

Returns:

Distance

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

checkRange

public void checkRange(DBIDRange range)

Description copied from interface: DBIDRangeDistanceFunction

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

Parameters:

range - DBID range