// Copyright (C) 2010 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_ONE_VS_ONE_DECISION_FUnCTION_Hh_
#define DLIB_ONE_VS_ONE_DECISION_FUnCTION_Hh_
#include "one_vs_one_decision_function_abstract.h"
#include "../serialize.h"
#include "../type_safe_union.h"
#include <iostream>
#include <sstream>
#include <set>
#include <map>
#include "../any.h"
#include "../unordered_pair.h"
#include "null_df.h"
namespace dlib
{
// ----------------------------------------------------------------------------------------
template <
typename one_vs_one_trainer,
typename DF1 = null_df, typename DF2 = null_df, typename DF3 = null_df,
typename DF4 = null_df, typename DF5 = null_df, typename DF6 = null_df,
typename DF7 = null_df, typename DF8 = null_df, typename DF9 = null_df,
typename DF10 = null_df
>
class one_vs_one_decision_function
{
public:
typedef typename one_vs_one_trainer::label_type result_type;
typedef typename one_vs_one_trainer::sample_type sample_type;
typedef typename one_vs_one_trainer::scalar_type scalar_type;
typedef typename one_vs_one_trainer::mem_manager_type mem_manager_type;
typedef std::map<unordered_pair<result_type>, any_decision_function<sample_type, scalar_type> > binary_function_table;
one_vs_one_decision_function() :num_classes(0) {}
explicit one_vs_one_decision_function(
const binary_function_table& dfs_
) : dfs(dfs_)
{
#ifdef ENABLE_ASSERTS
{
const std::vector<unordered_pair<result_type> > missing_pairs = find_missing_pairs(dfs_);
if (missing_pairs.size() != 0)
{
std::ostringstream sout;
for (unsigned long i = 0; i < missing_pairs.size(); ++i)
{
sout << "\t (" << missing_pairs[i].first << ", " << missing_pairs[i].second << ")\n";
}
DLIB_ASSERT(missing_pairs.size() == 0,
"\t void one_vs_one_decision_function::one_vs_one_decision_function()"
<< "\n\t The supplied set of binary decision functions is incomplete."
<< "\n\t this: " << this
<< "\n\t Classifiers are missing for the following label pairs: \n" << sout.str()
);
}
}
#endif
// figure out how many labels are covered by this set of binary decision functions
std::set<result_type> labels;
for (typename binary_function_table::const_iterator i = dfs.begin(); i != dfs.end(); ++i)
{
labels.insert(i->first.first);
labels.insert(i->first.second);
}
num_classes = labels.size();
}
const binary_function_table& get_binary_decision_functions (
) const
{
return dfs;
}
const std::vector<result_type> get_labels (
) const
{
std::set<result_type> labels;
for (typename binary_function_table::const_iterator i = dfs.begin(); i != dfs.end(); ++i)
{
labels.insert(i->first.first);
labels.insert(i->first.second);
}
return std::vector<result_type>(labels.begin(), labels.end());
}
template <
typename df1, typename df2, typename df3, typename df4, typename df5,
typename df6, typename df7, typename df8, typename df9, typename df10
>
one_vs_one_decision_function (
const one_vs_one_decision_function<one_vs_one_trainer,
df1, df2, df3, df4, df5,
df6, df7, df8, df9, df10>& item
) : dfs(item.get_binary_decision_functions()), num_classes(item.number_of_classes()) {}
unsigned long number_of_classes (
) const
{
return num_classes;
}
result_type operator() (
const sample_type& sample
) const
{
DLIB_ASSERT(number_of_classes() != 0,
"\t void one_vs_one_decision_function::operator()"
<< "\n\t You can't make predictions with an empty decision function."
<< "\n\t this: " << this
);
std::map<result_type,int> votes;
// run all the classifiers over the sample
for(typename binary_function_table::const_iterator i = dfs.begin(); i != dfs.end(); ++i)
{
const scalar_type score = i->second(sample);
if (score > 0)
votes[i->first.first] += 1;
else
votes[i->first.second] += 1;
}
// now figure out who had the most votes
result_type best_label = result_type();
int best_votes = 0;
for (typename std::map<result_type,int>::iterator i = votes.begin(); i != votes.end(); ++i)
{
if (i->second > best_votes)
{
best_votes = i->second;
best_label = i->first;
}
}
return best_label;
}
private:
binary_function_table dfs;
unsigned long num_classes;
};
// ----------------------------------------------------------------------------------------
template <
typename T,
typename DF1, typename DF2, typename DF3,
typename DF4, typename DF5, typename DF6,
typename DF7, typename DF8, typename DF9,
typename DF10
>
void serialize(
const one_vs_one_decision_function<T,DF1,DF2,DF3,DF4,DF5,DF6,DF7,DF8,DF9,DF10>& item,
std::ostream& out
)
{
try
{
type_safe_union<DF1,DF2,DF3,DF4,DF5,DF6,DF7,DF8,DF9,DF10> temp;
typedef typename T::label_type result_type;
typedef typename T::sample_type sample_type;
typedef typename T::scalar_type scalar_type;
typedef std::map<unordered_pair<result_type>, any_decision_function<sample_type, scalar_type> > binary_function_table;
const unsigned long version = 1;
serialize(version, out);
const unsigned long size = item.get_binary_decision_functions().size();
serialize(size, out);
for(typename binary_function_table::const_iterator i = item.get_binary_decision_functions().begin();
i != item.get_binary_decision_functions().end(); ++i)
{
serialize(i->first, out);
if (i->second.template contains<DF1>()) temp.template get<DF1>() = any_cast<DF1>(i->second);
else if (i->second.template contains<DF2>()) temp.template get<DF2>() = any_cast<DF2>(i->second);
else if (i->second.template contains<DF3>()) temp.template get<DF3>() = any_cast<DF3>(i->second);
else if (i->second.template contains<DF4>()) temp.template get<DF4>() = any_cast<DF4>(i->second);
else if (i->second.template contains<DF5>()) temp.template get<DF5>() = any_cast<DF5>(i->second);
else if (i->second.template contains<DF6>()) temp.template get<DF6>() = any_cast<DF6>(i->second);
else if (i->second.template contains<DF7>()) temp.template get<DF7>() = any_cast<DF7>(i->second);
else if (i->second.template contains<DF8>()) temp.template get<DF8>() = any_cast<DF8>(i->second);
else if (i->second.template contains<DF9>()) temp.template get<DF9>() = any_cast<DF9>(i->second);
else if (i->second.template contains<DF10>()) temp.template get<DF10>() = any_cast<DF10>(i->second);
else throw serialization_error("Can't serialize one_vs_one_decision_function. Not all decision functions defined.");
serialize(temp,out);
}
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while serializing an object of type one_vs_one_decision_function");
}
}
// ----------------------------------------------------------------------------------------
namespace impl
{
template <typename sample_type, typename scalar_type>
struct copy_to_df_helper
{
copy_to_df_helper(any_decision_function<sample_type, scalar_type>& target_) : target(target_) {}
any_decision_function<sample_type, scalar_type>& target;
template <typename T>
void operator() (
const T& item
) const
{
target = item;
}
};
}
template <
typename T,
typename DF1, typename DF2, typename DF3,
typename DF4, typename DF5, typename DF6,
typename DF7, typename DF8, typename DF9,
typename DF10
>
void deserialize(
one_vs_one_decision_function<T,DF1,DF2,DF3,DF4,DF5,DF6,DF7,DF8,DF9,DF10>& item,
std::istream& in
)
{
try
{
type_safe_union<DF1,DF2,DF3,DF4,DF5,DF6,DF7,DF8,DF9,DF10> temp;
typedef typename T::label_type result_type;
typedef typename T::sample_type sample_type;
typedef typename T::scalar_type scalar_type;
typedef impl::copy_to_df_helper<sample_type, scalar_type> copy_to;
unsigned long version;
deserialize(version, in);
if (version != 1)
throw serialization_error("Can't deserialize one_vs_one_decision_function. Wrong version.");
unsigned long size;
deserialize(size, in);
typedef std::map<unordered_pair<result_type>, any_decision_function<sample_type, scalar_type> > binary_function_table;
binary_function_table dfs;
unordered_pair<result_type> p;
for (unsigned long i = 0; i < size; ++i)
{
deserialize(p, in);
deserialize(temp, in);
if (temp.template contains<null_df>())
throw serialization_error("A sub decision function of unknown type was encountered.");
temp.apply_to_contents(copy_to(dfs[p]));
}
item = one_vs_one_decision_function<T,DF1,DF2,DF3,DF4,DF5,DF6,DF7,DF8,DF9,DF10>(dfs);
}
catch (serialization_error& e)
{
throw serialization_error(e.info + "\n while deserializing an object of type one_vs_one_decision_function");
}
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_ONE_VS_ONE_DECISION_FUnCTION_Hh_