de.lmu.ifi.dbs.elki.index.vafile

Class VectorApproximation

java.lang.Object

de.lmu.ifi.dbs.elki.index.vafile.VectorApproximation

public class VectorApproximation
extends java.lang.Object

Object in a VA approximation.

Since:

0.5.0

Author:

Thomas Bernecker, Erich Schubert

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int[]	approximation approximation (va cell ids)
protected DBID	id Object represented by this approximation

Constructor Summary

Constructors

Constructor and Description
VectorApproximation(DBID id, int[] approximation) Constructor.

Method Summary

Modifier and Type	Method and Description
static int	byteOnDisk(int numberOfDimensions, int numberOfPartitions) Computes IO costs (in bytes) needed for reading the candidates.
int	getApproximation(int dim) Get the VA approximation
int	getDimensionality() Get the dimensionality
DBID	getId()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

approximation

int[] approximation

approximation (va cell ids)

id

protected DBID id

Object represented by this approximation

Constructor Detail

VectorApproximation

public VectorApproximation(DBID id,
                           int[] approximation)

Constructor.

Parameters:

id - Object represented (may be null for query objects)

approximation - Approximation

Method Detail

getId

public DBID getId()

Returns:

the id

getDimensionality

public int getDimensionality()

Get the dimensionality

Returns:

Dimensionality

getApproximation

public int getApproximation(int dim)

Get the VA approximation

Parameters:

dim - Dimension

Returns:

Bin number

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

byteOnDisk

public static int byteOnDisk(int numberOfDimensions,
                             int numberOfPartitions)

Computes IO costs (in bytes) needed for reading the candidates. For one object, log2(numberOfPartitions) bits have to be read per dimension.

Parameters:

numberOfDimensions - the number of relevant dimensions

numberOfPartitions - the number of relevant partitions

Returns:

the cost values (in bytes)