#include <nearest_neighbor_classifier.hpp>

Inheritance diagram for jubatus::core::classifier::nearest_neighbor_classifier:

Collaboration diagram for jubatus::core::classifier::nearest_neighbor_classifier:

Classes
class	unlearning_callback

Public Member Functions
std::string	classify (const common::sfv_t &fv) const

void	classify_with_scores (const common::sfv_t &fv, classify_result &scores) const

void	clear ()

bool	delete_label (const std::string &label)

std::vector< std::string >	get_labels () const

framework::mixable *	get_mixable ()

void	get_status (std::map< std::string, std::string > &status) const

std::string	name () const

	nearest_neighbor_classifier (jubatus::util::lang::shared_ptr< nearest_neighbor::nearest_neighbor_base > nearest_neighbor_engine, size_t k, float alpha)

void	pack (framework::packer &pk) const

bool	set_label (const std::string &label)

void	set_label_unlearner (jubatus::util::lang::shared_ptr< unlearner::unlearner_base > label_unlearner)

void	train (const common::sfv_t &fv, const std::string &label)

void	unpack (msgpack::object o)

Public Member Functions inherited from jubatus::core::classifier::classifier_base
	classifier_base ()

virtual	~classifier_base ()

Private Member Functions
void	unlearn_id (const std::string &id)

Private Attributes
float	alpha_

size_t	k_

jubatus::util::data::unordered_set< std::string >	labels_

jubatus::util::lang::shared_ptr< nearest_neighbor::nearest_neighbor_base >	nearest_neighbor_engine_

jubatus::util::math::random::mtrand	rand_

jubatus::util::concurrent::mutex	rand_mutex_

jubatus::util::lang::shared_ptr< unlearner::unlearner_base >	unlearner_

jubatus::util::concurrent::mutex	unlearner_mutex_

Detailed Description

Definition at line 40 of file nearest_neighbor_classifier.hpp.

Constructor & Destructor Documentation

jubatus::core::classifier::nearest_neighbor_classifier::nearest_neighbor_classifier	(	jubatus::util::lang::shared_ptr< nearest_neighbor::nearest_neighbor_base >	nearest_neighbor_engine,
		size_t	k,
		float	alpha
	)

Definition at line 75 of file nearest_neighbor_classifier.cpp.

References JUBATUS_EXCEPTION.

     : nearest_neighbor_engine_(engine), k_(k), alpha_(alpha) {
   if (!(alpha >= 0)) {
     throw JUBATUS_EXCEPTION(common::invalid_parameter(
         "local_sensitivity should >= 0"));
   }
 }

Member Function Documentation

std::string jubatus::core::classifier::nearest_neighbor_classifier::classify ( const common::sfv_t & fv ) const

Definition at line 110 of file nearest_neighbor_classifier.cpp.

References classify_with_scores().

                                  {
   classify_result result;
   classify_with_scores(fv, result);
   float max_score = -FLT_MAX;
   std::string max_class;
   for (std::vector<classify_result_elem>::const_iterator it = result.begin();
       it != result.end(); ++it) {
     if (it == result.begin() || it->score > max_score) {
       max_score = it->score;
       max_class = it->label;
     }
   }
   return max_class;
 }

Here is the call graph for this function:

void jubatus::core::classifier::nearest_neighbor_classifier::classify_with_scores	(	const common::sfv_t &	fv,
		classify_result &	scores
	)		const

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 126 of file nearest_neighbor_classifier.cpp.

References alpha_, k_, labels_, and nearest_neighbor_engine_.

Referenced by classify().

                                                           {
   std::vector<std::pair<std::string, float> > ids;
   nearest_neighbor_engine_->neighbor_row(fv, ids, k_);
 
   std::map<std::string, float> m;
   for (unordered_set<std::string>::const_iterator iter = labels_.begin();
        iter != labels_.end(); ++iter) {
     m.insert(std::make_pair(*iter, 0));
   }
   for (size_t i = 0; i < ids.size(); ++i) {
     std::string label = get_label_from_id(ids[i].first);
     m[label] += std::exp(-alpha_ * ids[i].second);
   }
 
   scores.clear();
   for (std::map<std::string, float>::const_iterator iter = m.begin();
        iter != m.end(); ++iter) {
     classify_result_elem elem(iter->first, iter->second);
     scores.push_back(elem);
   }
 }

Here is the caller graph for this function:

void jubatus::core::classifier::nearest_neighbor_classifier::clear ( )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 177 of file nearest_neighbor_classifier.cpp.

References labels_, nearest_neighbor_engine_, and unlearner_.

                                         {
   nearest_neighbor_engine_->clear();
   labels_.clear();
   if (unlearner_) {
     unlearner_->clear();
   }
 }

bool jubatus::core::classifier::nearest_neighbor_classifier::delete_label ( const std::string & label )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 149 of file nearest_neighbor_classifier.cpp.

References labels_, nearest_neighbor_engine_, and unlearner_.

                                                                      {
   if (labels_.erase(label) == 0) {
     return false;
   }
 
   shared_ptr<storage::column_table> table =
       nearest_neighbor_engine_->get_table();
 
   std::vector<std::string> ids_to_be_deleted;
   for (size_t i = 0, n = table->size(); i < n; ++i) {
     std::string id = table->get_key(i);
     std::string l = get_label_from_id(id);
     if (l == label) {
       ids_to_be_deleted.push_back(id);
     }
   }
 
   for (size_t i = 0, n = ids_to_be_deleted.size(); i < n; ++i) {
     const std::string& id = ids_to_be_deleted[i];
     table->delete_row(id);
     if (unlearner_) {
       unlearner_->remove(id);
     }
   }
 
   return true;
 }

std::vector< std::string > jubatus::core::classifier::nearest_neighbor_classifier::get_labels ( ) const

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 185 of file nearest_neighbor_classifier.cpp.

References labels_.

                                                                    {
   std::vector<std::string> result;
   for (unordered_set<std::string>::const_iterator iter = labels_.begin();
        iter != labels_.end(); ++iter) {
     result.push_back(*iter);
   }
   return result;
 }

framework::mixable * jubatus::core::classifier::nearest_neighbor_classifier::get_mixable ( )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 235 of file nearest_neighbor_classifier.cpp.

References nearest_neighbor_engine_.

                                                            {
   return nearest_neighbor_engine_->get_mixable();
 }

void jubatus::core::classifier::nearest_neighbor_classifier::get_status ( std::map< std::string, std::string > & status ) const

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 202 of file nearest_neighbor_classifier.cpp.

                                                 {
   // unimplemented
 }

std::string jubatus::core::classifier::nearest_neighbor_classifier::name ( ) const

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 198 of file nearest_neighbor_classifier.cpp.

References nearest_neighbor_engine_.

                                                   {
   return "nearest_neighbor_classifier:" + nearest_neighbor_engine_->type();
 }

void jubatus::core::classifier::nearest_neighbor_classifier::pack ( framework::packer & pk ) const

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 207 of file nearest_neighbor_classifier.cpp.

References labels_, and nearest_neighbor_engine_.

                                                                 {
   pk.pack_array(2);
   nearest_neighbor_engine_->pack(pk);
 
   pk.pack_array(labels_.size());
   for (unordered_set<std::string>::const_iterator iter = labels_.begin();
        iter != labels_.end(); ++iter) {
     pk.pack(*iter);
   }
 }

bool jubatus::core::classifier::nearest_neighbor_classifier::set_label ( const std::string & label )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 194 of file nearest_neighbor_classifier.cpp.

References labels_.

Referenced by train().

                                                                   {
   return labels_.insert(label).second;
 }

Here is the caller graph for this function:

void jubatus::core::classifier::nearest_neighbor_classifier::set_label_unlearner ( jubatus::util::lang::shared_ptr< unlearner::unlearner_base > label_unlearner )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 104 of file nearest_neighbor_classifier.cpp.

References unlearner_.

                                                          {
   label_unlearner->set_callback(unlearning_callback(this));
   unlearner_ = label_unlearner;
 }

void jubatus::core::classifier::nearest_neighbor_classifier::train	(	const common::sfv_t &	fv,
		const std::string &	label
	)

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 86 of file nearest_neighbor_classifier.cpp.

References JUBATUS_EXCEPTION, nearest_neighbor_engine_, rand_, rand_mutex_, set_label(), unlearner_, and unlearner_mutex_.

                                                    {
   std::string id;
   {
     util::concurrent::scoped_lock lk(rand_mutex_);
     id = make_id_from_label(label, rand_);
   }
   if (unlearner_) {
     util::concurrent::scoped_lock unlearner_lk(unlearner_mutex_);
     if (!unlearner_->touch(id)) {
       throw JUBATUS_EXCEPTION(common::exception::runtime_error(
           "no more space available to add new ID: " + id));
     }
   }
   nearest_neighbor_engine_->set_row(id, fv);
   set_label(label);
 }

Here is the call graph for this function:

void jubatus::core::classifier::nearest_neighbor_classifier::unlearn_id ( const std::string & id )

private

Definition at line 239 of file nearest_neighbor_classifier.cpp.

References nearest_neighbor_engine_.

Referenced by jubatus::core::classifier::nearest_neighbor_classifier::unlearning_callback::operator()().

                                                                 {
   nearest_neighbor_engine_->get_table()->delete_row(id);
 }

Here is the caller graph for this function:

void jubatus::core::classifier::nearest_neighbor_classifier::unpack ( msgpack::object o )

virtual

Implements jubatus::core::classifier::classifier_base.

Definition at line 218 of file nearest_neighbor_classifier.cpp.

References labels_, and nearest_neighbor_engine_.

                                                         {
   if (o.type != msgpack::type::ARRAY || o.via.array.size != 2) {
     throw msgpack::type_error();
   }
   nearest_neighbor_engine_->unpack(o.via.array.ptr[0]);
 
   msgpack::object labels = o.via.array.ptr[1];
   if (labels.type != msgpack::type::ARRAY) {
     throw msgpack::type_error();
   }
   for (size_t i = 0; i < labels.via.array.size; ++i) {
     std::string label;
     labels.via.array.ptr[i].convert(&label);
     labels_.insert(label);
   }
 }

Member Data Documentation

float jubatus::core::classifier::nearest_neighbor_classifier::alpha_

private

Definition at line 76 of file nearest_neighbor_classifier.hpp.

Referenced by classify_with_scores().

size_t jubatus::core::classifier::nearest_neighbor_classifier::k_

private

Definition at line 75 of file nearest_neighbor_classifier.hpp.

Referenced by classify_with_scores().

jubatus::util::data::unordered_set<std::string> jubatus::core::classifier::nearest_neighbor_classifier::labels_

private

Definition at line 74 of file nearest_neighbor_classifier.hpp.

Referenced by classify_with_scores(), clear(), delete_label(), get_labels(), pack(), set_label(), and unpack().

jubatus::util::lang::shared_ptr<nearest_neighbor::nearest_neighbor_base> jubatus::core::classifier::nearest_neighbor_classifier::nearest_neighbor_engine_

private

Definition at line 73 of file nearest_neighbor_classifier.hpp.

Referenced by classify_with_scores(), clear(), delete_label(), get_mixable(), name(), pack(), train(), unlearn_id(), and unpack().