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CGaussianShiftKernel Class Reference

Detailed Description

An experimental kernel inspired by the WeightedDegreePositionStringKernel and the Gaussian kernel.

It is computed as

\[ k({\bf x},{\bf x'})= \exp(-\frac{||{\bf x}-{\bf x'}||^2}{\tau}) + \sum_{s=1}^{S_{\mathrm{max}}/S_{\mathrm{step}}} \frac{1}{2s} \exp(-\frac{||{\bf x}_{[1:|{\bf x}|-sS_{\mathrm{step}}]}-{\bf x'}_{[sS_{\mathrm{step}}:|{\bf x}|]}||^2}{\tau}) + \sum_{s=1}^{S_{max}/S_{step}} \frac{1}{2s} \exp(-\frac{||{\bf x}_{[sS_{\mathrm{step}}:|{\bf x}|]}-{\bf x'}_{[1:|{\bf x}|-sS_{\mathrm{step}}]}||^2}{\tau}) + \]

where $\tau$ is the kernel width. The idea is to shift the dimensions of the input vectors against eachother. $S_{\mathrm{step}}$ is the step size (parameter shift_step) of the shifts and $S_{\mathrm{max}}$ (parameter max_shift) is the maximal shift.

Definition at line 37 of file GaussianShiftKernel.h.

Inheritance diagram for CGaussianShiftKernel:
Inheritance graph
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Public Member Functions

 CGaussianShiftKernel ()
 CGaussianShiftKernel (int32_t size, float64_t width, int32_t max_shift, int32_t shift_step)
 CGaussianShiftKernel (CSimpleFeatures< float64_t > *l, CSimpleFeatures< float64_t > *r, float64_t width, int32_t max_shift, int32_t shift_step, int32_t size=10)
virtual ~CGaussianShiftKernel ()
virtual EKernelType get_kernel_type ()
virtual const char * get_name () const
- Public Member Functions inherited from CGaussianKernel
 CGaussianKernel ()
 CGaussianKernel (int32_t size, float64_t width)
 CGaussianKernel (CDotFeatures *l, CDotFeatures *r, float64_t width, int32_t size=10)
virtual ~CGaussianKernel ()
virtual bool init (CFeatures *l, CFeatures *r)
virtual void cleanup ()
virtual void set_width (float64_t w)
virtual float64_t get_width () const
void set_compact_enabled (bool compact)
bool get_compact_enabled ()
- 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_tget_kernel_matrix ()
virtual SGVector< float64_tget_kernel_col (int32_t j)
virtual SGVector< float64_tget_kernel_row (int32_t i)
template<class T >
SGMatrix< T > get_kernel_matrix ()
virtual bool set_normalizer (CKernelNormalizer *normalizer)
virtual CKernelNormalizerget_normalizer ()
virtual bool init_normalizer ()
void load (CFile *loader)
void save (CFile *writer)
CFeaturesget_lhs ()
CFeaturesget_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_tget_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)
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)
- Protected Member Functions inherited from CGaussianKernel
virtual void load_serializable_post () throw (ShogunException)

Protected Attributes

int32_t max_shift
int32_t shift_step
- Protected Attributes inherited from CGaussianKernel
float64_t width
float64_tsq_lhs
float64_tsq_rhs
bool m_compact

Additional Inherited Members

- Public Attributes inherited from CSGObject
SGIOio
Parallelparallel
Versionversion
Parameterm_parameters
Parameterm_model_selection_parameters
- Static Protected Member Functions inherited from CKernel
template<class T >
static void * get_kernel_matrix_helper (void *p)

Constructor & Destructor Documentation

default constructor

Definition at line 19 of file GaussianShiftKernel.cpp.

CGaussianShiftKernel ( int32_t  size,
float64_t  width,
int32_t  max_shift,
int32_t  shift_step 
)

constructor

Parameters
sizecache size
widthwidth
max_shiftmaximum shift
shift_stepshift step

Definition at line 25 of file GaussianShiftKernel.cpp.

CGaussianShiftKernel ( CSimpleFeatures< float64_t > *  l,
CSimpleFeatures< float64_t > *  r,
float64_t  width,
int32_t  max_shift,
int32_t  shift_step,
int32_t  size = 10 
)

constructor

Parameters
lfeatures of left-hand side
rfeatures of right-hand side
widthwidth
max_shiftmaximum shift
shift_stepshift step
sizecache size

Definition at line 32 of file GaussianShiftKernel.cpp.

~CGaussianShiftKernel ( )
virtual

Definition at line 41 of file GaussianShiftKernel.cpp.

Member Function Documentation

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_aindex a
idx_bindex b
Returns
computed kernel function at indices a,b

Reimplemented from CGaussianKernel.

Definition at line 45 of file GaussianShiftKernel.cpp.

virtual EKernelType get_kernel_type ( )
virtual

return what type of kernel we are

Returns
kernel type GAUSSIANSHIFT

Reimplemented from CGaussianKernel.

Definition at line 74 of file GaussianShiftKernel.h.

virtual const char* get_name ( ) const
virtual

return the kernel's name

Returns
name GaussianShift

Reimplemented from CGaussianKernel.

Definition at line 80 of file GaussianShiftKernel.h.

Member Data Documentation

int32_t max_shift
protected

maximum shift

Definition at line 98 of file GaussianShiftKernel.h.

int32_t shift_step
protected

shift step

Definition at line 100 of file GaussianShiftKernel.h.


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

SHOGUN Machine Learning Toolbox - Documentation