CMatchWordStringKernel Class Reference

Inheritance diagram for CMatchWordStringKernel:

Inheritance graph
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List of all members.

Public Member Functions

 CMatchWordStringKernel (int32_t size, int32_t d)
 CMatchWordStringKernel (CStringFeatures< uint16_t > *l, CStringFeatures< uint16_t > *r, int32_t degree)
virtual ~CMatchWordStringKernel ()
virtual bool init (CFeatures *l, CFeatures *r)
virtual bool load_init (FILE *src)
virtual bool save_init (FILE *dest)
virtual EKernelType get_kernel_type ()
virtual const char * get_name ()

Protected Member Functions

virtual float64_t compute (int32_t idx_a, int32_t idx_b)

Protected Attributes

int32_t degree


Detailed Description

The class MatchWordStringKernel computes a variant of the polynomial kernel on strings of same length converted to a word alphabet. It is computed as

\[ k({\bf x},{\bf x'})= \sum_{i=0}^L I(x_i=x'_i)+c)^d \]

where I is the indicator function which evaluates to 1 if its argument is true and to 0 otherwise.

Note that additional normalisation is applied, i.e.

\[ k'({\bf x}, {\bf x'})=\frac{k({\bf x}, {\bf x'})}{\sqrt{k({\bf x}, {\bf x})k({\bf x'}, {\bf x'})}} \]

Definition at line 32 of file MatchWordStringKernel.h.


Constructor & Destructor Documentation

CMatchWordStringKernel::CMatchWordStringKernel ( int32_t  size,
int32_t  d 
)

constructor

Parameters:
size cache size
d degree

Definition at line 18 of file MatchWordStringKernel.cpp.

CMatchWordStringKernel::CMatchWordStringKernel ( CStringFeatures< uint16_t > *  l,
CStringFeatures< uint16_t > *  r,
int32_t  degree 
)

constructor

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

Definition at line 24 of file MatchWordStringKernel.cpp.

CMatchWordStringKernel::~CMatchWordStringKernel (  )  [virtual]

Definition at line 31 of file MatchWordStringKernel.cpp.


Member Function Documentation

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

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

Implements CKernel.

Definition at line 52 of file MatchWordStringKernel.cpp.

virtual EKernelType CMatchWordStringKernel::get_kernel_type (  )  [virtual]

return what type of kernel we are

Returns:
kernel type LINEAR

Implements CKernel.

Definition at line 78 of file MatchWordStringKernel.h.

virtual const char* CMatchWordStringKernel::get_name (  )  [virtual]

return the kernel's name

Returns:
name MatchWordString

Implements CKernel.

Definition at line 84 of file MatchWordStringKernel.h.

bool CMatchWordStringKernel::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 CStringKernel< uint16_t >.

Definition at line 36 of file MatchWordStringKernel.cpp.

bool CMatchWordStringKernel::load_init ( FILE *  src  )  [virtual]

load kernel init_data

Parameters:
src file to load from
Returns:
if loading was successful

Implements CKernel.

Definition at line 42 of file MatchWordStringKernel.cpp.

bool CMatchWordStringKernel::save_init ( FILE *  dest  )  [virtual]

save kernel init_data

Parameters:
dest file to save to
Returns:
if saving was successful

Implements CKernel.

Definition at line 47 of file MatchWordStringKernel.cpp.


Member Data Documentation

int32_t CMatchWordStringKernel::degree [protected]

degree

Definition at line 99 of file MatchWordStringKernel.h.


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

SHOGUN Machine Learning Toolbox - Documentation