Public Member Functions | Protected Attributes

CMultitaskKernelNormalizer Class Reference


Detailed Description

The MultitaskKernel allows Multitask Learning via a modified kernel function.

This effectively normalizes the vectors in feature space to norm 1 (see CSqrtDiagKernelNormalizer)

\[ k'({\bf x},{\bf x'}) = \gamma(task({\bf x}),task({\bf x'})) k({\bf x},{\bf x'}) \]

Definition at line 31 of file MultitaskKernelNormalizer.h.

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

Public Member Functions

 CMultitaskKernelNormalizer ()
 CMultitaskKernelNormalizer (std::vector< int32_t > task_vector)
virtual ~CMultitaskKernelNormalizer ()
virtual bool init (CKernel *k)
int32_t get_num_unique_tasks (std::vector< int32_t > vec)
virtual float64_t normalize (float64_t value, int32_t idx_lhs, int32_t idx_rhs)
virtual float64_t normalize_lhs (float64_t value, int32_t idx_lhs)
virtual float64_t normalize_rhs (float64_t value, int32_t idx_rhs)
std::vector< int32_t > get_task_vector_lhs () const
void set_task_vector_lhs (std::vector< int32_t > vec)
std::vector< int32_t > get_task_vector_rhs () const
void set_task_vector_rhs (std::vector< int32_t > vec)
void set_task_vector (std::vector< int32_t > vec)
float64_t get_task_similarity (int32_t task_lhs, int32_t task_rhs)
void set_task_similarity (int32_t task_lhs, int32_t task_rhs, float64_t similarity)
virtual const char * get_name () const
CMultitaskKernelNormalizerKernelNormalizerToMultitaskKernelNormalizer (CKernelNormalizer *n)

Protected Attributes

std::vector< float64_tsimilarity_matrix
int32_t num_tasks
std::vector< int32_t > task_vector_lhs
std::vector< int32_t > task_vector_rhs
float64_t scale

Constructor & Destructor Documentation

default constructor

Definition at line 38 of file MultitaskKernelNormalizer.h.

CMultitaskKernelNormalizer ( std::vector< int32_t >  task_vector  ) 

default constructor

Parameters:
task_vector task vector with containing task_id for each example

Definition at line 46 of file MultitaskKernelNormalizer.h.

virtual ~CMultitaskKernelNormalizer (  )  [virtual]

default destructor

Definition at line 61 of file MultitaskKernelNormalizer.h.


Member Function Documentation

virtual const char* get_name (  )  const [virtual]
Returns:
object name

Implements CSGObject.

Definition at line 228 of file MultitaskKernelNormalizer.h.

int32_t get_num_unique_tasks ( std::vector< int32_t >  vec  ) 

helper routine

Parameters:
vec vector with containing task_id for each example
Returns:
number of unique task ids

Definition at line 103 of file MultitaskKernelNormalizer.h.

float64_t get_task_similarity ( int32_t  task_lhs,
int32_t  task_rhs 
)
Parameters:
task_lhs task_id on left hand side
task_rhs task_id on right hand side
Returns:
similarity between tasks

Definition at line 201 of file MultitaskKernelNormalizer.h.

std::vector<int32_t> get_task_vector_lhs (  )  const
Returns:
vec task vector with containing task_id for each example on left hand side

Definition at line 166 of file MultitaskKernelNormalizer.h.

std::vector<int32_t> get_task_vector_rhs (  )  const
Returns:
vec task vector with containing task_id for each example on right hand side

Definition at line 178 of file MultitaskKernelNormalizer.h.

virtual bool init ( CKernel k  )  [virtual]

initialization of the normalizer

Parameters:
k kernel

Implements CKernelNormalizer.

Definition at line 67 of file MultitaskKernelNormalizer.h.

CMultitaskKernelNormalizer* KernelNormalizerToMultitaskKernelNormalizer ( CKernelNormalizer n  ) 

convert generic kernel normalizer object into CMultitaskKernelNormalizer

Returns:
converted CMultitaskKernelNormalizer object

Definition at line 237 of file MultitaskKernelNormalizer.h.

virtual float64_t normalize ( float64_t  value,
int32_t  idx_lhs,
int32_t  idx_rhs 
) [virtual]

normalize the kernel value

Parameters:
value kernel value
idx_lhs index of left hand side vector
idx_rhs index of right hand side vector

Implements CKernelNormalizer.

Definition at line 123 of file MultitaskKernelNormalizer.h.

virtual float64_t normalize_lhs ( float64_t  value,
int32_t  idx_lhs 
) [virtual]

normalize only the left hand side vector

Parameters:
value value of a component of the left hand side feature vector
idx_lhs index of left hand side vector

Implements CKernelNormalizer.

Definition at line 147 of file MultitaskKernelNormalizer.h.

virtual float64_t normalize_rhs ( float64_t  value,
int32_t  idx_rhs 
) [virtual]

normalize only the right hand side vector

Parameters:
value value of a component of the right hand side feature vector
idx_rhs index of right hand side vector

Implements CKernelNormalizer.

Definition at line 157 of file MultitaskKernelNormalizer.h.

void set_task_similarity ( int32_t  task_lhs,
int32_t  task_rhs,
float64_t  similarity 
)
Parameters:
task_lhs task_id on left hand side
task_rhs task_id on right hand side
similarity similarity between tasks

Definition at line 216 of file MultitaskKernelNormalizer.h.

void set_task_vector ( std::vector< int32_t >  vec  ) 
Parameters:
vec task vector with containing task_id for each example

Definition at line 190 of file MultitaskKernelNormalizer.h.

void set_task_vector_lhs ( std::vector< int32_t >  vec  ) 
Parameters:
vec task vector with containing task_id for each example

Definition at line 172 of file MultitaskKernelNormalizer.h.

void set_task_vector_rhs ( std::vector< int32_t >  vec  ) 
Parameters:
vec task vector with containing task_id for each example

Definition at line 184 of file MultitaskKernelNormalizer.h.


Member Data Documentation

int32_t num_tasks [protected]

number of tasks

Definition at line 249 of file MultitaskKernelNormalizer.h.

float64_t scale [protected]

scale constant obtained from k(0,0)

Definition at line 258 of file MultitaskKernelNormalizer.h.

std::vector<float64_t> similarity_matrix [protected]

MxM matrix encoding similarity between tasks

Definition at line 246 of file MultitaskKernelNormalizer.h.

std::vector<int32_t> task_vector_lhs [protected]

task vector indicating to which task each example on the left hand side belongs

Definition at line 252 of file MultitaskKernelNormalizer.h.

std::vector<int32_t> task_vector_rhs [protected]

task vector indicating to which task each example on the right hand side belongs

Definition at line 255 of file MultitaskKernelNormalizer.h.


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