CDPL.Descr.EuclideanSimilarity Class Reference

Functor class for calculating the Euclidean Similarity [GSIM] of bitsets. More...

Inheritance diagram for CDPL.Descr.EuclideanSimilarity:

Public Member Functions
None	__init__ ()
	Initializes the EuclideanSimilarity instance.
None	__init__ (EuclideanSimilarity func)
	Initializes a copy of the EuclideanSimilarity instance func. More...
int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...
EuclideanSimilarity	assign (EuclideanSimilarity func)
	Replaces the current state of self with a copy of the state of the EuclideanSimilarity instance func. More...
float	__call__ (Util.BitSet bs1, Util.BitSet bs2)
	Calculates the Euclidean Similarity [GSIM] of the bitsets bs1 and bs2. More...

Properties
	objectID = property(getObjectID)

Detailed Description

Functor class for calculating the Euclidean Similarity [GSIM] of bitsets.

Constructor & Destructor Documentation

__init__()

None CDPL.Descr.EuclideanSimilarity.__init__

(

EuclideanSimilarity

func

)

Initializes a copy of the EuclideanSimilarity instance func.

Parameters

func	The EuclideanSimilarity instance to copy.

Member Function Documentation

getObjectID()

int CDPL.Descr.EuclideanSimilarity.getObjectID

(

)

Returns the numeric identifier (ID) of the wrapped C++ class instance.

Different Python EuclideanSimilarity instances may reference the same underlying C++ class instance. The commonly used Python expression a is not b thus cannot tell reliably whether the two EuclideanSimilarity instances a and b reference different C++ objects. The numeric identifier returned by this method allows to correctly implement such an identity test via the simple expression a.getObjectID() != b.getObjectID().

Returns

The numeric ID of the internally referenced C++ class instance.

assign()

EuclideanSimilarity CDPL.Descr.EuclideanSimilarity.assign

(

EuclideanSimilarity

func

)

Replaces the current state of self with a copy of the state of the EuclideanSimilarity instance func.

Parameters

func	The EuclideanSimilarity instance to copy.

Returns

self

__call__()

float CDPL.Descr.EuclideanSimilarity.__call__	(	Util.BitSet	bs1,
		Util.BitSet	bs2
	)

Calculates the Euclidean Similarity [GSIM] of the bitsets bs1 and bs2.

The Euclidean Similarity $S_{ab}$ is calculated by:

[ S_{ab} = \sqrt{\frac{N_{ab} + N_{!ab}}{N_a + N_b + N_{ab} + N_{!ab}}} ]

where $N_{ab}$ is the number of bits that are set in both bitsets, $N_a$ is the number of bits that are set only in the first bitset, $N_b$ is the number of bits that are set only in the second bitset and $N_{!ab}$ is the number of bits that are not set in both bitsets.

If the specified bitsets bs1 and bs2 are of different size, missing bits at the end of the smaller bitset are assumed to be zero.

Parameters

bs1	The first bitset.
bs2	The second bitset.

Returns

The calculated similarity measure.