Detailed Description

The standard Sigmoid kernel computed on dense real valued features.

Formally, it is computed as

$k({\bf x},{\bf x'})=\mbox{tanh}(\gamma {\bf x}\cdot{\bf x'}+c)$

Definition at line 29 of file SigmoidKernel.h.

Inheritance diagram for CSigmoidKernel:

Public Member Functions
	CSigmoidKernel ()
	CSigmoidKernel (int32_t size, float64_t gamma, float64_t coef0)
	CSigmoidKernel (CDotFeatures l, CDotFeatures r, int32_t size, float64_t gamma, float64_t coef0)
virtual	~CSigmoidKernel ()
virtual bool	init (CFeatures l, CFeatures r)
virtual void	cleanup ()
virtual EKernelType	get_kernel_type ()
virtual const char *	get_name () const
Public Member Functions inherited from CDotKernel
	CDotKernel ()
	CDotKernel (int32_t cachesize)
	CDotKernel (CFeatures l, CFeatures r)
virtual EFeatureClass	get_feature_class ()
virtual EFeatureType	get_feature_type ()
Public Member Functions inherited from CKernel
	CKernel ()
	CKernel (int32_t size)
	CKernel (CFeatures l, CFeatures r, int32_t size)
virtual	~CKernel ()
float64_t	kernel (int32_t idx_a, int32_t idx_b)
SGMatrix< float64_t >	get_kernel_matrix ()
virtual SGVector< float64_t >	get_kernel_col (int32_t j)
virtual SGVector< float64_t >	get_kernel_row (int32_t i)
template<class T >
SGMatrix< T >	get_kernel_matrix ()
virtual bool	set_normalizer (CKernelNormalizer *normalizer)
virtual CKernelNormalizer *	get_normalizer ()
virtual bool	init_normalizer ()
void	load (CFile *loader)
void	save (CFile *writer)
CFeatures *	get_lhs ()
CFeatures *	get_rhs ()
virtual int32_t	get_num_vec_lhs ()
virtual int32_t	get_num_vec_rhs ()
virtual bool	has_features ()
bool	get_lhs_equals_rhs ()
virtual void	remove_lhs_and_rhs ()
virtual void	remove_lhs ()
virtual void	remove_rhs ()
	takes all necessary steps if the rhs is removed from kernel
void	set_cache_size (int32_t size)
int32_t	get_cache_size ()
void	list_kernel ()
bool	has_property (EKernelProperty p)
virtual void	clear_normal ()
virtual void	add_to_normal (int32_t vector_idx, float64_t weight)
EOptimizationType	get_optimization_type ()
virtual void	set_optimization_type (EOptimizationType t)
bool	get_is_initialized ()
virtual bool	init_optimization (int32_t count, int32_t IDX, float64_t weights)
virtual bool	delete_optimization ()
bool	init_optimization_svm (CSVM *svm)
virtual float64_t	compute_optimized (int32_t vector_idx)
virtual void	compute_batch (int32_t num_vec, int32_t vec_idx, float64_t target, int32_t num_suppvec, int32_t IDX, float64_t alphas, float64_t factor=1.0)
float64_t	get_combined_kernel_weight ()
void	set_combined_kernel_weight (float64_t nw)
virtual int32_t	get_num_subkernels ()
virtual void	compute_by_subkernel (int32_t vector_idx, float64_t *subkernel_contrib)
virtual const float64_t *	get_subkernel_weights (int32_t &num_weights)
virtual void	set_subkernel_weights (SGVector< float64_t > weights)
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)
SGIO *	get_global_io ()
void	set_global_parallel (Parallel *parallel)
Parallel *	get_global_parallel ()
void	set_global_version (Version *version)
Version *	get_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)

Protected Attributes
float64_t	gamma
float64_t	coef0

Additional Inherited Members
Public Attributes inherited from CSGObject
SGIO *	io
Parallel *	parallel
Version *	version
Parameter *	m_parameters
Parameter *	m_model_selection_parameters
Static Protected Member Functions inherited from CKernel
template<class T >
static void *	get_kernel_matrix_helper (void *p)

Constructor & Destructor Documentation

CSigmoidKernel ( )

default constructor

Definition at line 17 of file SigmoidKernel.cpp.

CSigmoidKernel	(	int32_t	size,
		float64_t	gamma,
		float64_t	coef0
	)

constructor

Parameters

size	cache size
gamma	gamma
coef0	coefficient 0

Definition at line 22 of file SigmoidKernel.cpp.

CSigmoidKernel	(	CDotFeatures *	l,
		CDotFeatures *	r,
		int32_t	size,
		float64_t	gamma,
		float64_t	coef0
	)

constructor

Parameters

l	features of left-hand side
r	features of right-hand side
size	cache size
gamma	gamma
coef0	coefficient 0

Definition at line 31 of file SigmoidKernel.cpp.

~CSigmoidKernel ( )

virtual

Definition at line 43 of file SigmoidKernel.cpp.

Member Function Documentation

void cleanup ( )

virtual

clean up kernel

Reimplemented from CKernel.

Definition at line 48 of file SigmoidKernel.cpp.

virtual float64_t compute	(	int32_t	idx_a,
		int32_t	idx_b
	)

protectedvirtual

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

Parameters

idx_a	index a
idx_b	index b

Returns: computed kernel function at indices a,b

Reimplemented from CDotKernel.

Definition at line 88 of file SigmoidKernel.h.

virtual EKernelType get_kernel_type ( )

virtual

return what type of kernel we are

Returns: kernel type SIGMOID

Implements CDotKernel.

Definition at line 71 of file SigmoidKernel.h.

virtual const char* get_name ( ) const

virtual

return the kernel's name

Returns: name Sigmoid

Reimplemented from CDotKernel.

Definition at line 77 of file SigmoidKernel.h.

bool init	(	CFeatures *	l,
		CFeatures *	r
	)

virtual

initialize kernel

Parameters

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

Returns: if initializing was successful

Reimplemented from CDotKernel.

Definition at line 52 of file SigmoidKernel.cpp.

Member Data Documentation

float64_t coef0

protected

coefficient 0

Definition at line 100 of file SigmoidKernel.h.

float64_t gamma

protected

gamma

Definition at line 98 of file SigmoidKernel.h.

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

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation