de.lmu.ifi.dbs.elki.algorithm.itemsetmining

Class SparseItemset

java.lang.Object

de.lmu.ifi.dbs.elki.algorithm.itemsetmining.Itemset

de.lmu.ifi.dbs.elki.algorithm.itemsetmining.SparseItemset

All Implemented Interfaces:

Comparable<Itemset>

public class SparseItemset
extends Itemset

APRIORI itemset.

Author:

Erich Schubert

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int[]	indices Items, as indexes.

Fields inherited from class de.lmu.ifi.dbs.elki.algorithm.itemsetmining.Itemset

support

Constructor Summary

Constructors

Constructor and Description
SparseItemset(int[] indices) Constructor.
SparseItemset(int[] indices, int support) Constructor.
SparseItemset(OneItemset ii, OneItemset ij) Constructor from existing itemsets.

Method Summary

Modifier and Type	Method and Description
StringBuilder	appendTo(StringBuilder buf, VectorFieldTypeInformation<BitVector> meta) Append to a string buffer.
int	compareTo(Itemset o)
boolean	containedIn(BitVector bv) Test whether the itemset is contained in a bit vector.
boolean	equals(Object obj)
long[]	getItems() Get the items.
int	hashCode()
int	length() Itemset length.
boolean	prefixTest(SparseItemset other) Perform the prefix test for sparse itemset.

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.itemsetmining.Itemset

getSupport, increaseSupport, toString

Methods inherited from class java.lang.Object

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

Field Detail

indices

int[] indices

Items, as indexes.

Constructor Detail

SparseItemset

public SparseItemset(int[] indices)

Constructor.

Parameters:

indices - Items

SparseItemset

public SparseItemset(int[] indices,
                     int support)

Constructor.

Parameters:

indices - Items

support - Support

SparseItemset

public SparseItemset(OneItemset ii,
                     OneItemset ij)

Constructor from existing itemsets.

Parameters:

ii - First 1-itemset

ij - Second 1-itemset

Method Detail

length

public int length()

Description copied from class: Itemset

Itemset length.

Specified by:

length in class Itemset

Returns:

Itemset length

containedIn

public boolean containedIn(BitVector bv)

Description copied from class: Itemset

Test whether the itemset is contained in a bit vector.

Specified by:

containedIn in class Itemset

Parameters:

bv - Bit vector

Returns:

true when the itemset is contained in this vector.

getItems

public long[] getItems()

Description copied from class: Itemset

Get the items.

Specified by:

getItems in class Itemset

Returns:

Itemset contents.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

compareTo

public int compareTo(Itemset o)

appendTo

public StringBuilder appendTo(StringBuilder buf,
                              VectorFieldTypeInformation<BitVector> meta)

Description copied from class: Itemset

Append to a string buffer.

Specified by:

appendTo in class Itemset

Parameters:

buf - Buffer

meta - Relation metadata (for labels)

Returns:

String buffer for chaining.

prefixTest

public boolean prefixTest(SparseItemset other)

Perform the prefix test for sparse itemset.

Parameters:

other - Other itemset

Returns:

true iff the first n-1 items agree.