Public Member Functions | Protected Member Functions

CJensenMetric Class Reference


Detailed Description

class JensenMetric

The Jensen-Shannon distance/divergence measures the similarity between two data points which is based on the Kullback-Leibler divergence.

\[\displaystyle d(\bf{x},\bf{x'}) = \sum_{i=0}^{n} x_{i} log\frac{x_{i}}{0.5(x_{i} +x'_{i})} + x'_{i} log\frac{x'_{i}}{0.5(x_{i}+x'_{i})} \]

See also:
Wikipedia: Jensen-Shannon divergence
Wikipedia: Kullback-Leibler divergence

Definition at line 35 of file JensenMetric.h.

Inheritance diagram for CJensenMetric:
Inheritance graph
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List of all members.

Public Member Functions

 CJensenMetric ()
 CJensenMetric (CSimpleFeatures< float64_t > *l, CSimpleFeatures< float64_t > *r)
virtual ~CJensenMetric ()
virtual bool init (CFeatures *l, CFeatures *r)
virtual void cleanup ()
virtual EDistanceType get_distance_type ()
virtual const char * get_name () const

Protected Member Functions

virtual float64_t compute (int32_t idx_a, int32_t idx_b)

Constructor & Destructor Documentation

CJensenMetric (  ) 

default constructor

Definition at line 20 of file JensenMetric.cpp.

constructor

Parameters:
l features of left-hand side
r features of right-hand side

Definition at line 24 of file JensenMetric.cpp.

~CJensenMetric (  )  [virtual]

Definition at line 30 of file JensenMetric.cpp.


Member Function Documentation

void cleanup (  )  [virtual]

cleanup distance

Implements CSimpleDistance< float64_t >.

Definition at line 40 of file JensenMetric.cpp.

float64_t compute ( int32_t  idx_a,
int32_t  idx_b 
) [protected, virtual]

compute distance for features a and b idx_{a,b} denote the index of the feature vectors in the corresponding feature object

Implements CDistance.

Definition at line 44 of file JensenMetric.cpp.

virtual EDistanceType get_distance_type (  )  [virtual]

get distance type we are

Returns:
distance type JENSEN

Implements CSimpleDistance< float64_t >.

Definition at line 64 of file JensenMetric.h.

virtual const char* get_name ( void   )  const [virtual]

get name of the distance

Returns:
name Jensen-Metric

Reimplemented from CSimpleDistance< float64_t >.

Definition at line 70 of file JensenMetric.h.

bool init ( CFeatures l,
CFeatures r 
) [virtual]

init distance

Parameters:
l features of left-hand side
r features of right-hand side
Returns:
if init was successful

Reimplemented from CSimpleDistance< float64_t >.

Definition at line 35 of file JensenMetric.cpp.


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