de.lmu.ifi.dbs.elki.data

Class BitVector

java.lang.Object

de.lmu.ifi.dbs.elki.data.AbstractNumberVector

de.lmu.ifi.dbs.elki.data.BitVector

All Implemented Interfaces:

FeatureVector<Number>, NumberVector, SparseFeatureVector<Number>, SparseNumberVector, SpatialComparable

public class BitVector
extends AbstractNumberVector
implements SparseNumberVector

Vector using a dense bit set encoding, based on long[] storage.

Author:

Arthur Zimek

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BitVector.Factory Factory for bit vectors.
static class	BitVector.ShortSerializer Serialization class for dense integer vectors with up to Short.MAX_VALUE dimensions, by using a short for storing the dimensionality.

Field Summary

Fields

Modifier and Type	Field and Description
private long[]	bits Storing the bits.
private int	dimensionality Dimensionality of this bit vector.
static BitVector.Factory	FACTORY Static instance.
static ByteBufferSerializer<BitVector>	SHORT_SERIALIZER Serializer for up to 2^15-1 dimensions.

Fields inherited from class de.lmu.ifi.dbs.elki.data.AbstractNumberVector

ATTRIBUTE_SEPARATOR

Constructor Summary

Constructors

Constructor and Description
BitVector(long[] bits, int dimensionality) Create a new BitVector corresponding to the specified bits and of the specified dimensionality.

Method Summary

Methods

Modifier and Type	Method and Description
void	andOnto(long[] v) Combine onto v using the AND operation, i.e.
boolean	booleanValue(int dimension) Get the value of a single bit.
int	cardinality() Compute the vector cardinality (uncached!)
long[]	cloneBits() Returns a copy of the bits currently set in this BitVector.
boolean	contains(long[] bitset) Returns whether this BitVector contains all bits that are set to true in the specified BitSet.
double	doubleValue(int dimension) Returns the value in the specified dimension as double.
boolean	equals(Object obj) Indicates whether some other object is "equal to" this BitVector.
Vector	getColumnVector() Returns a Vector representing in one column and getDimensionality() rows the values of this BitVector as double values.
int	getDimensionality() The dimensionality of the vector space where of this FeatureVector of V is an element.
Bit	getValue(int dimension) Deprecated.
int	hammingDistance(BitVector v2) Compute the Hamming distance of two bit vectors.
boolean	intersect(BitVector v2) Compute whether two vectors intersect.
int	intersectionSize(BitVector v2) Compute the vector intersection size.
int	iter() Iterator over non-zero features only, ascendingly.
int	iterAdvance(int iter) Advance the iterator to the next position.
byte	iterByteValue(int iter) Get the value of the iterators' current dimension.
int	iterDim(int iter) Get the dimension an iterator points to.
double	iterDoubleValue(int iter) Get the value of the iterators' current dimension.
float	iterFloatValue(int iter) Get the value of the iterators' current dimension.
int	iterIntValue(int iter) Get the value of the iterators' current dimension.
long	iterLongValue(int iter) Get the value of the iterators' current dimension.
short	iterShortValue(int iter) Get the value of the iterators' current dimension.
boolean	iterValid(int iter) Test the iterator position for validity.
double	jaccardSimilarity(BitVector v2) Compute the Jaccard similarity of two bit vectors.
long	longValue(int dimension) Returns the value in the specified dimension as long.
void	orOnto(long[] v) Combine onto v using the OR operation, i.e.
void	setDimensionality(int dimensionality) Update the vector space dimensionality.
String	toString() Returns a String representation of this BitVector.
int	unionSize(BitVector v2) Compute the vector union size.
void	xorOnto(long[] v) Combine onto v using the XOR operation, i.e.

Methods inherited from class de.lmu.ifi.dbs.elki.data.AbstractNumberVector

byteValue, floatValue, getMax, getMin, intValue, shortValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.data.SparseNumberVector

byteValue, floatValue, intValue, shortValue

Methods inherited from interface de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable

getMax, getMin

Field Detail

FACTORY

public static final BitVector.Factory FACTORY

Static instance.

SHORT_SERIALIZER

public static final ByteBufferSerializer<BitVector> SHORT_SERIALIZER

Serializer for up to 2^15-1 dimensions.

bits

private final long[] bits

Storing the bits.

dimensionality

private int dimensionality

Dimensionality of this bit vector.

Constructor Detail

BitVector

public BitVector(long[] bits,
         int dimensionality)

Create a new BitVector corresponding to the specified bits and of the specified dimensionality.

Parameters:

bits - the bits to be set in this BitVector.

dimensionality - the dimensionality of this BitVector

Method Detail

getDimensionality

public int getDimensionality()

Description copied from interface: FeatureVector

The dimensionality of the vector space where of this FeatureVector of V is an element.

Specified by:

getDimensionality in interface FeatureVector<Number>

Specified by:

getDimensionality in interface SpatialComparable

Returns:

the number of dimensions of this FeatureVector of V

setDimensionality

public void setDimensionality(int dimensionality)

Description copied from interface: SparseNumberVector

Update the vector space dimensionality.

Specified by:

setDimensionality in interface SparseNumberVector

Parameters:

dimensionality - New dimensionality

booleanValue

public boolean booleanValue(int dimension)

Get the value of a single bit.

Parameters:

dimension - Bit number to get

Returns:

true when set

getValue

@Deprecated
public Bit getValue(int dimension)

Deprecated.

Description copied from interface: FeatureVector

Returns the value in the specified dimension.

Specified by:

getValue in interface FeatureVector<Number>

Specified by:

getValue in interface NumberVector

Parameters:

dimension - the desired dimension, where 0 ≤ dimension ≤ this.getDimensionality()-1

Returns:

the value in the specified dimension

doubleValue

public double doubleValue(int dimension)

Description copied from interface: NumberVector

Returns the value in the specified dimension as double. Note: this might seem redundant with respect to getValue(dim).doubleValue(), but usually this is much more efficient due to boxing/unboxing cost.

Specified by:

doubleValue in interface NumberVector

Specified by:

doubleValue in interface SparseNumberVector

Parameters:

dimension - the desired dimension, where 0 ≤ dimension < this.getDimensionality()

Returns:

the value in the specified dimension

longValue

public long longValue(int dimension)

Description copied from interface: NumberVector

Returns the value in the specified dimension as long. Note: this might seem redundant with respect to getValue(dim).longValue(), but usually this is much more efficient due to boxing/unboxing cost.

Specified by:

longValue in interface NumberVector

Specified by:

longValue in interface SparseNumberVector

Parameters:

dimension - the desired dimension, where 0 ≤ dimension < this.getDimensionality()

Returns:

the value in the specified dimension

iter

public int iter()

Description copied from interface: SparseNumberVector

Iterator over non-zero features only, ascendingly. Note: depending on the underlying implementation, this may or may not be the dimension. Use SparseFeatureVector.iterDim(int) to get the actual dimension. In fact, usually this will be the ith non-zero value, assuming an array representation. Think of this number as an iterator. For efficiency, it has a primitive type! Intended usage:

 for (int iter = v.iter(); v.iterValid(iter); iter = v.iterAdvance(iter)) {
   final int dim = v.iterDim(iter);
   final double val = v.iterDoubleValue(iter);
   // Do something.
 }
 
 

Specified by:

iter in interface SparseFeatureVector<Number>

Specified by:

iter in interface SparseNumberVector

Returns:

Identifier for the first non-zero dimension, not necessarily the dimension!

iterAdvance

public int iterAdvance(int iter)

Description copied from interface: SparseFeatureVector

Advance the iterator to the next position.

Specified by:

iterAdvance in interface SparseFeatureVector<Number>

Parameters:

iter - Previous iterator position

Returns:

Next iterator position

iterValid

public boolean iterValid(int iter)

Description copied from interface: SparseFeatureVector

Test the iterator position for validity.

Specified by:

iterValid in interface SparseFeatureVector<Number>

Parameters:

iter - Iterator position

Returns:

true when it refers to a valid position.

iterDim

public int iterDim(int iter)

Description copied from interface: SparseFeatureVector

Get the dimension an iterator points to.

Specified by:

iterDim in interface SparseFeatureVector<Number>

Parameters:

iter - Iterator position

Returns:

Dimension the iterator refers to

iterDoubleValue

public double iterDoubleValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterDoubleValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

iterFloatValue

public float iterFloatValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterFloatValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

iterIntValue

public int iterIntValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterIntValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

iterShortValue

public short iterShortValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterShortValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

iterLongValue

public long iterLongValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterLongValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

iterByteValue

public byte iterByteValue(int iter)

Description copied from interface: SparseNumberVector

Get the value of the iterators' current dimension.

Specified by:

iterByteValue in interface SparseNumberVector

Parameters:

iter - Iterator

Returns:

Value at the current position

getColumnVector

public Vector getColumnVector()

Returns a Vector representing in one column and getDimensionality() rows the values of this BitVector as double values.

Specified by:

getColumnVector in interface NumberVector

Returns:

a Matrix representing in one column and getDimensionality() rows the values of this BitVector as double values

See Also:

NumberVector.getColumnVector()

contains

public boolean contains(long[] bitset)

Returns whether this BitVector contains all bits that are set to true in the specified BitSet.

Parameters:

bitset - the bits to inspect in this BitVector

Returns:

true if this BitVector contains all bits that are set to true in the specified BitSet, false otherwise

cloneBits

public long[] cloneBits()

Returns a copy of the bits currently set in this BitVector.

Returns:

a copy of the bits currently set in this BitVector

cardinality

public int cardinality()

Compute the vector cardinality (uncached!)

Returns:

Vector cardinality

jaccardSimilarity

public double jaccardSimilarity(BitVector v2)

Compute the Jaccard similarity of two bit vectors.

Parameters:

v2 - Second bit vector

Returns:

Jaccard similarity (intersection / union)

hammingDistance

public int hammingDistance(BitVector v2)

Compute the Hamming distance of two bit vectors.

Parameters:

v2 - Second bit vector

Returns:

Hamming distance (number of bits difference)

intersectionSize

public int intersectionSize(BitVector v2)

Compute the vector intersection size.

Parameters:

v2 - Second bit vector

Returns:

Intersection size (number of bits in both)

unionSize

public int unionSize(BitVector v2)

Compute the vector union size.

Parameters:

v2 - Second bit vector

Returns:

Intersection size (number of bits in both)

intersect

public boolean intersect(BitVector v2)

Compute whether two vectors intersect.

Parameters:

v2 - Second bit vector

Returns:

true if they intersect in at least one bit.

andOnto

public void andOnto(long[] v)

Combine onto v using the AND operation, i.e. v &= this.

Parameters:

v - Existing bit set of same length.

orOnto

public void orOnto(long[] v)

Combine onto v using the OR operation, i.e. v |= this.

Parameters:

v - Existing bit set of same length.

xorOnto

public void xorOnto(long[] v)

Combine onto v using the XOR operation, i.e. v ^= this.

Parameters:

v - Existing bit set of same length.

toString

public String toString()

Returns a String representation of this BitVector. The representation is suitable to be parsed by BitVectorLabelParser. Returns a String representation of the FeatureVector of V as a line that is suitable to be printed in a sequential file.

Specified by:

toString in interface FeatureVector<Number>

Overrides:

toString in class Object

Returns:

a String representation of the FeatureVector of V

equals

public boolean equals(Object obj)

Indicates whether some other object is "equal to" this BitVector. This BitVector is equal to the given object, if the object is a BitVector of same dimensionality and with identical bits set.

Overrides:

equals in class Object