CDPL.Descr.DiceSimilarity Class Reference

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

Inheritance diagram for CDPL.Descr.DiceSimilarity:

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

Properties
	objectID = property(getObjectID)

Detailed Description

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

Constructor & Destructor Documentation

__init__()

None CDPL.Descr.DiceSimilarity.__init__

(

DiceSimilarity

func

)

Initializes a copy of the DiceSimilarity instance func.

Parameters

func	The DiceSimilarity instance to copy.

Member Function Documentation

getObjectID()

int CDPL.Descr.DiceSimilarity.getObjectID

(

)

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

Different Python DiceSimilarity 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 DiceSimilarity 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()

DiceSimilarity CDPL.Descr.DiceSimilarity.assign

(

DiceSimilarity

func

)

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

Parameters

func	The DiceSimilarity instance to copy.

Returns

self

__call__()

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

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

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

[ S_{ab} = \frac{2 * N_{ab}}{N_a + N_b + 2 * 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 only set in the first bitset and $N_b$ is the number of bits that are only set in the second bitset.

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.