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CChiSquareDistance Class Reference

Detailed Description

class ChiSquareDistance

This implementation of $\chi^{2}$ distance extends the concept of $\chi^{2}$ metric to negative values.

\[\displaystyle d(\bf{x},\bf{x'}) = \sum_{i=1}^{n}\frac{(x_{i}-x'_{i})^2} {|x_{i}|+|x'_{i}|} \quad \bf{x},\bf{x'} \in R^{n} \]

See Also
K. Rieck, P. Laskov. Linear-Time Computation of Similarity Measures for Sequential Data. Journal of Machine Learning Research, 9:23–48,2008.

Definition at line 33 of file ChiSquareDistance.h.

Inheritance diagram for CChiSquareDistance:
Inheritance graph
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Public Member Functions

 CChiSquareDistance ()
 CChiSquareDistance (CSimpleFeatures< float64_t > *l, CSimpleFeatures< float64_t > *r)
virtual ~CChiSquareDistance ()
virtual bool init (CFeatures *l, CFeatures *r)
virtual void cleanup ()
virtual EDistanceType get_distance_type ()
virtual const char * get_name () const
- Public Member Functions inherited from CSimpleDistance< float64_t >
 CSimpleDistance ()
virtual EFeatureClass get_feature_class ()
virtual EFeatureType get_feature_type ()
- Public Member Functions inherited from CDistance
 CDistance ()
 CDistance (CFeatures *lhs, CFeatures *rhs)
virtual ~CDistance ()
float64_t distance (int32_t idx_a, int32_t idx_b)
SGMatrix< float64_tget_distance_matrix ()
virtual float64_tget_distance_matrix_real (int32_t &m, int32_t &n, float64_t *target)
virtual float32_tget_distance_matrix_shortreal (int32_t &m, int32_t &n, float32_t *target)
void load (CFile *loader)
void save (CFile *writer)
CFeaturesget_lhs ()
CFeaturesget_rhs ()
CFeaturesreplace_rhs (CFeatures *rhs)
virtual void remove_lhs_and_rhs ()
virtual void remove_lhs ()
 takes all necessary steps if the lhs is removed from distance matrix
virtual void remove_rhs ()
 takes all necessary steps if the rhs is removed from distance matrix
bool get_precompute_matrix ()
virtual void set_precompute_matrix (bool flag)
int32_t get_num_vec_lhs ()
int32_t get_num_vec_rhs ()
bool has_features ()
bool lhs_equals_rhs ()
- Public Member Functions inherited from CSGObject
 CSGObject ()
 CSGObject (const CSGObject &orig)
virtual ~CSGObject ()
virtual bool is_generic (EPrimitiveType *generic) const
template<class T >
void set_generic ()
void unset_generic ()
virtual void print_serializable (const char *prefix="")
virtual bool save_serializable (CSerializableFile *file, const char *prefix="")
virtual bool load_serializable (CSerializableFile *file, const char *prefix="")
void set_global_io (SGIO *io)
SGIOget_global_io ()
void set_global_parallel (Parallel *parallel)
Parallelget_global_parallel ()
void set_global_version (Version *version)
Versionget_global_version ()
SGVector< char * > get_modelsel_names ()
char * get_modsel_param_descr (const char *param_name)
index_t get_modsel_param_index (const char *param_name)

Protected Member Functions

virtual float64_t compute (int32_t idx_a, int32_t idx_b)

Additional Inherited Members

- Public Attributes inherited from CSGObject
SGIOio
Parallelparallel
Versionversion
Parameterm_parameters
Parameterm_model_selection_parameters
- Static Protected Member Functions inherited from CDistance
static void * run_distance_thread (void *p)
 run distance thread
- Protected Attributes inherited from CDistance
float32_tprecomputed_matrix
bool precompute_matrix
CFeatureslhs
 feature vectors to occur on left hand side
CFeaturesrhs
 feature vectors to occur on right hand side

Constructor & Destructor Documentation

default constructor

Definition at line 20 of file ChiSquareDistance.cpp.

constructor

Parameters
lfeatures of left-hand side
rfeatures of right-hand side

Definition at line 24 of file ChiSquareDistance.cpp.

~CChiSquareDistance ( )
virtual

Definition at line 30 of file ChiSquareDistance.cpp.

Member Function Documentation

void cleanup ( )
virtual

cleanup distance

Implements CSimpleDistance< float64_t >.

Definition at line 42 of file ChiSquareDistance.cpp.

float64_t compute ( int32_t  idx_a,
int32_t  idx_b 
)
protectedvirtual

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 46 of file ChiSquareDistance.cpp.

virtual EDistanceType get_distance_type ( )
virtual

get distance type we are

Returns
distance type CHISQUARE

Implements CSimpleDistance< float64_t >.

Definition at line 62 of file ChiSquareDistance.h.

virtual const char* get_name ( ) const
virtual

get name of the distance

Returns
name Chi-square distance

Reimplemented from CSimpleDistance< float64_t >.

Definition at line 68 of file ChiSquareDistance.h.

bool init ( CFeatures l,
CFeatures r 
)
virtual

init distance

Parameters
lfeatures of left-hand side
rfeatures of right-hand side
Returns
if init was successful

Reimplemented from CSimpleDistance< float64_t >.

Definition at line 35 of file ChiSquareDistance.cpp.


The documentation for this class was generated from the following files:

SHOGUN Machine Learning Toolbox - Documentation