# CECOCRandomSparseEncoder Class Reference

## Detailed Description

ECOC Random Sparse Encoder.

Given probabilities P(0), P(+1) and P(-1) (that sums to 1), the codebook element is randomly selected according to those probabilities. However, to avoid generating invalid code (i.e. not both +1 and -1 are present), we use a heuristic modification here:

1. randomly select two positions and assign them (+1,-1) or (-1,+1) with probability 0.5, 0.5 respectively 2. random sample and assign values to the rest of the code positions

In this way, we guarantee that both +1 and -1 are present in the code. However, the effective probability is changed to Q. Assume number of classes is K, then

* Q(0) = (K-2)/K * P(0) * Q(+1) = 1/K + (K-2)/K * P(+1) * Q(-1) = 1/K + (K-2)/K * P(-1)

Definition at line 36 of file ECOCRandomSparseEncoder.h.

Inheritance diagram for CECOCRandomSparseEncoder:
[legend]

List of all members.

## Public Member Functions

CECOCRandomSparseEncoder (int32_t maxiter=10000, int32_t codelen=0, float64_t pzero=0.5, float64_t pposone=0.25, float64_t pnegone=0.25)
virtual ~CECOCRandomSparseEncoder ()
void set_probability (float64_t pzero, float64_t pposone, float64_t pnegone)
virtual const char * get_name () const
int32_t get_default_code_length (int32_t num_classes) const
virtual SGMatrix< int32_t > create_codebook (int32_t num_classes)
virtual CSGObjectshallow_copy () const
virtual CSGObjectdeep_copy () const
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="", int32_t param_version=VERSION_PARAMETER)
virtual bool load_serializable (CSerializableFile *file, const char *prefix="", int32_t param_version=VERSION_PARAMETER)
DynArray< TParameter * > * load_file_parameters (const SGParamInfo *param_info, int32_t file_version, CSerializableFile *file, const char *prefix="")
DynArray< TParameter * > * load_all_file_parameters (int32_t file_version, int32_t current_version, CSerializableFile *file, const char *prefix="")
void map_parameters (DynArray< TParameter * > *param_base, int32_t &base_version, DynArray< const SGParamInfo * > *target_param_infos)
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 ()
SGStringList< char > get_modelsel_names ()
void print_modsel_params ()
char * get_modsel_param_descr (const char *param_name)
index_t get_modsel_param_index (const char *param_name)
void build_parameter_dictionary (CMap< TParameter *, CSGObject * > &dict)

## Public Attributes

SGIOio
Parallelparallel
Versionversion
Parameterm_parameters
Parameterm_model_selection_parameters
ParameterMapm_parameter_map
uint32_t m_hash

## Protected Member Functions

virtual TParametermigrate (DynArray< TParameter * > *param_base, const SGParamInfo *target)
virtual void one_to_one_migration_prepare (DynArray< TParameter * > *param_base, const SGParamInfo *target, TParameter *&replacement, TParameter *&to_migrate, char *old_name=NULL)
virtual void load_serializable_pre () throw (ShogunException)
virtual void load_serializable_post () throw (ShogunException)
virtual void save_serializable_pre () throw (ShogunException)
virtual void save_serializable_post () throw (ShogunException)
virtual bool update_parameter_hash ()

## Protected Attributes

int32_t m_maxiter
int32_t m_codelen
float64_t m_pzero
float64_t m_pposone
float64_t m_pnegone

## Constructor & Destructor Documentation

 CECOCRandomSparseEncoder ( int32_t maxiter = `10000`, int32_t codelen = `0`, float64_t pzero = `0.5`, float64_t pposone = `0.25`, float64_t pnegone = `0.25` )

constructor

Parameters:
 maxiter max number of iterations codelen code length, if set to zero, will be computed automatically via get_default_code_length pzero probability of zero pposone probability of +1 pnegone probability of -1
get_default_code_length

Definition at line 20 of file ECOCRandomSparseEncoder.cpp.

 virtual ~CECOCRandomSparseEncoder ( ) ` [virtual]`

destructor

Definition at line 52 of file ECOCRandomSparseEncoder.h.

## Member Function Documentation

 void build_parameter_dictionary ( CMap< TParameter *, CSGObject * > & dict ) ` [inherited]`

Builds a dictionary of all parameters in SGObject as well of those of SGObjects that are parameters of this object. Dictionary maps parameters to the objects that own them.

Parameters:
 dict dictionary of parameters to be built.

Definition at line 1201 of file SGObject.cpp.

 SGMatrix< int32_t > create_codebook ( int32_t num_classes ) ` [virtual]`

init codebook.

Parameters:
 num_classes number of classes in this problem

Implements CECOCEncoder.

Definition at line 49 of file ECOCRandomSparseEncoder.cpp.

 virtual CSGObject* deep_copy ( ) const` [virtual, inherited]`

A deep copy. All the instance variables will also be copied.

Definition at line 131 of file SGObject.h.

 int32_t get_default_code_length ( int32_t num_classes ) const

get default code length

Parameters:
 num_classes number of classes

In Sparse Random Coding, 15 * log(num_classes) is suggested as code length. See

S. Escalera, O. Pujol, and P. Radeva. Separability of ternary codes for sparse designs of error-correcting output codes. Pattern Recognition Letters, 30:285-297, 2009.

Definition at line 73 of file ECOCRandomSparseEncoder.h.

 SGIO * get_global_io ( ) ` [inherited]`

get the io object

Returns:
io object

Definition at line 224 of file SGObject.cpp.

 Parallel * get_global_parallel ( ) ` [inherited]`

get the parallel object

Returns:
parallel object

Definition at line 259 of file SGObject.cpp.

 Version * get_global_version ( ) ` [inherited]`

get the version object

Returns:
version object

Definition at line 272 of file SGObject.cpp.

 SGStringList< char > get_modelsel_names ( ) ` [inherited]`
Returns:
vector of names of all parameters which are registered for model selection

Definition at line 1108 of file SGObject.cpp.

 char * get_modsel_param_descr ( const char * param_name ) ` [inherited]`

Returns description of a given parameter string, if it exists. SG_ERROR otherwise

Parameters:
 param_name name of the parameter
Returns:
description of the parameter

Definition at line 1132 of file SGObject.cpp.

 index_t get_modsel_param_index ( const char * param_name ) ` [inherited]`

Returns index of model selection parameter with provided index

Parameters:
 param_name name of model selection parameter
Returns:
index of model selection parameter with provided name, -1 if there is no such

Definition at line 1145 of file SGObject.cpp.

 virtual const char* get_name ( ) const` [virtual]`

get name

Reimplemented from CECOCEncoder.

Definition at line 62 of file ECOCRandomSparseEncoder.h.

 bool is_generic ( EPrimitiveType * generic ) const` [virtual, inherited]`

If the SGSerializable is a class template then TRUE will be returned and GENERIC is set to the type of the generic.

Parameters:
 generic set to the type of the generic if returning TRUE
Returns:
TRUE if a class template.

Definition at line 278 of file SGObject.cpp.

 DynArray< TParameter * > * load_all_file_parameters ( int32_t file_version, int32_t current_version, CSerializableFile * file, const char * prefix = `""` ) ` [inherited]`

maps all parameters of this instance to the provided file version and loads all parameter data from the file into an array, which is sorted (basically calls load_file_parameter(...) for all parameters and puts all results into a sorted array)

Parameters:
 file_version parameter version of the file current_version version from which mapping begins (you want to use VERSION_PARAMETER for this in most cases) file file to load from prefix prefix for members
Returns:
(sorted) array of created TParameter instances with file data

Definition at line 679 of file SGObject.cpp.

 DynArray< TParameter * > * load_file_parameters ( const SGParamInfo * param_info, int32_t file_version, CSerializableFile * file, const char * prefix = `""` ) ` [inherited]`

loads some specified parameters from a file with a specified version The provided parameter info has a version which is recursively mapped until the file parameter version is reached. Note that there may be possibly multiple parameters in the mapping, therefore, a set of TParameter instances is returned

Parameters:
 param_info information of parameter file_version parameter version of the file, must be <= provided parameter version file file to load from prefix prefix for members
Returns:
new array with TParameter instances with the attached data

Definition at line 523 of file SGObject.cpp.

 bool load_serializable ( CSerializableFile * file, const char * prefix = `""`, int32_t param_version = `VERSION_PARAMETER` ) ` [virtual, inherited]`

Load this object from file. If it will fail (returning FALSE) then this object will contain inconsistent data and should not be used!

Parameters:
 file where to load from prefix prefix for members param_version (optional) a parameter version different to (this is mainly for testing, better do not use)
Returns:
TRUE if done, otherwise FALSE

Reimplemented in CModelSelectionParameters.

Definition at line 354 of file SGObject.cpp.

 void load_serializable_post ( ) throw (ShogunException)` [protected, virtual, inherited]`

Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_POST is called.

Exceptions:
 ShogunException Will be thrown if an error occurres.

Definition at line 1033 of file SGObject.cpp.

 void load_serializable_pre ( ) throw (ShogunException)` [protected, virtual, inherited]`

Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_PRE is called.

Exceptions:
 ShogunException Will be thrown if an error occurres.

Definition at line 1028 of file SGObject.cpp.

 void map_parameters ( DynArray< TParameter * > * param_base, int32_t & base_version, DynArray< const SGParamInfo * > * target_param_infos ) ` [inherited]`

Takes a set of TParameter instances (base) with a certain version and a set of target parameter infos and recursively maps the base level wise to the current version using CSGObject::migrate(...). The base is replaced. After this call, the base version containing parameters should be of same version/type as the initial target parameter infos. Note for this to work, the migrate methods and all the internal parameter mappings have to match

Parameters:
 param_base set of TParameter instances that are mapped to the provided target parameter infos base_version version of the parameter base target_param_infos set of SGParamInfo instances that specify the target parameter base

Definition at line 717 of file SGObject.cpp.

 TParameter * migrate ( DynArray< TParameter * > * param_base, const SGParamInfo * target ) ` [protected, virtual, inherited]`

creates a new TParameter instance, which contains migrated data from the version that is provided. The provided parameter data base is used for migration, this base is a collection of all parameter data of the previous version. Migration is done FROM the data in param_base TO the provided param info Migration is always one version step. Method has to be implemented in subclasses, if no match is found, base method has to be called.

If there is an element in the param_base which equals the target, a copy of the element is returned. This represents the case when nothing has changed and therefore, the migrate method is not overloaded in a subclass

Parameters:
 param_base set of TParameter instances to use for migration target parameter info for the resulting TParameter
Returns:
a new TParameter instance with migrated data from the base of the type which is specified by the target parameter

Definition at line 923 of file SGObject.cpp.

 void one_to_one_migration_prepare ( DynArray< TParameter * > * param_base, const SGParamInfo * target, TParameter *& replacement, TParameter *& to_migrate, char * old_name = `NULL` ) ` [protected, virtual, inherited]`

This method prepares everything for a one-to-one parameter migration. One to one here means that only ONE element of the parameter base is needed for the migration (the one with the same name as the target). Data is allocated for the target (in the type as provided in the target SGParamInfo), and a corresponding new TParameter instance is written to replacement. The to_migrate pointer points to the single needed TParameter instance needed for migration. If a name change happened, the old name may be specified by old_name. In addition, the m_delete_data flag of to_migrate is set to true. So if you want to migrate data, the only thing to do after this call is converting the data in the m_parameter fields. If unsure how to use - have a look into an example for this. (base_migration_type_conversion.cpp for example)

Parameters:
 param_base set of TParameter instances to use for migration target parameter info for the resulting TParameter replacement (used as output) here the TParameter instance which is returned by migration is created into to_migrate the only source that is used for migration old_name with this parameter, a name change may be specified

Definition at line 864 of file SGObject.cpp.

 void print_modsel_params ( ) ` [inherited]`

prints all parameter registered for model selection and their type

Definition at line 1084 of file SGObject.cpp.

 void print_serializable ( const char * prefix = `""` ) ` [virtual, inherited]`

prints registered parameters out

Parameters:
 prefix prefix for members

Definition at line 290 of file SGObject.cpp.

 bool save_serializable ( CSerializableFile * file, const char * prefix = `""`, int32_t param_version = `VERSION_PARAMETER` ) ` [virtual, inherited]`

Save this object to file.

Parameters:
 file where to save the object; will be closed during returning if PREFIX is an empty string. prefix prefix for members param_version (optional) a parameter version different to (this is mainly for testing, better do not use)
Returns:
TRUE if done, otherwise FALSE

Reimplemented in CModelSelectionParameters.

Definition at line 296 of file SGObject.cpp.

 void save_serializable_post ( ) throw (ShogunException)` [protected, virtual, inherited]`

Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_POST is called.

Exceptions:
 ShogunException Will be thrown if an error occurres.

Reimplemented in CKernel.

Definition at line 1043 of file SGObject.cpp.

 void save_serializable_pre ( ) throw (ShogunException)` [protected, virtual, inherited]`

Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_PRE is called.

Exceptions:
 ShogunException Will be thrown if an error occurres.

Reimplemented in CKernel.

Definition at line 1038 of file SGObject.cpp.

 void set_generic< floatmax_t > ( ) ` [inherited]`

set generic type to T

 void set_global_io ( SGIO * io ) ` [inherited]`

set the io object

Parameters:
 io io object to use

Definition at line 217 of file SGObject.cpp.

 void set_global_parallel ( Parallel * parallel ) ` [inherited]`

set the parallel object

Parameters:
 parallel parallel object to use

Definition at line 230 of file SGObject.cpp.

 void set_global_version ( Version * version ) ` [inherited]`

set the version object

Parameters:
 version version object to use

Definition at line 265 of file SGObject.cpp.

 void set_probability ( float64_t pzero, float64_t pposone, float64_t pnegone )

set probability

Parameters:
 pzero probability of zero pposone probability of +1 pnegone probability of -1

Definition at line 39 of file ECOCRandomSparseEncoder.cpp.

 virtual CSGObject* shallow_copy ( ) const` [virtual, inherited]`

A shallow copy. All the SGObject instance variables will be simply assigned and SG_REF-ed.

Reimplemented in CGaussianKernel.

Definition at line 122 of file SGObject.h.

 void unset_generic ( ) ` [inherited]`

unset generic type

this has to be called in classes specializing a template class

Definition at line 285 of file SGObject.cpp.

 bool update_parameter_hash ( ) ` [protected, virtual, inherited]`

Updates the hash of current parameter combination.

Returns:
bool if parameter combination has changed since last update.

Definition at line 237 of file SGObject.cpp.

## Member Data Documentation

 SGIO* io` [inherited]`

io

Definition at line 462 of file SGObject.h.

 int32_t m_codelen` [protected]`

code length

Definition at line 87 of file ECOCRandomSparseEncoder.h.

 uint32_t m_hash` [inherited]`

Hash of parameter values

Definition at line 480 of file SGObject.h.

 int32_t m_maxiter` [protected]`

maximum number of iterations

Definition at line 85 of file ECOCRandomSparseEncoder.h.

 Parameter* m_model_selection_parameters` [inherited]`

model selection parameters

Definition at line 474 of file SGObject.h.

 ParameterMap* m_parameter_map` [inherited]`

map for different parameter versions

Definition at line 477 of file SGObject.h.

 Parameter* m_parameters` [inherited]`

parameters

Definition at line 471 of file SGObject.h.

 float64_t m_pnegone` [protected]`

probability of -1

Definition at line 93 of file ECOCRandomSparseEncoder.h.

 float64_t m_pposone` [protected]`

probability of +1

Definition at line 91 of file ECOCRandomSparseEncoder.h.

 float64_t m_pzero` [protected]`

probability of zero

Definition at line 89 of file ECOCRandomSparseEncoder.h.

 Parallel* parallel` [inherited]`

parallel

Definition at line 465 of file SGObject.h.

 Version* version` [inherited]`

version

Definition at line 468 of file SGObject.h.

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

SHOGUN Machine Learning Toolbox - Documentation