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Added the histogram intersection kernel for sparse and dense vectors.

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This commit is contained in:
Davis King 2011-11-06 09:09:32 -05:00
parent 85db4e4ebb
commit b9149a5e74
4 changed files with 248 additions and 8 deletions
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46
dlib/svm/kernel.h
View File

@ -400,6 +400,52 @@ namespace dlib
const linear_kernel<T>& k;
};
// ----------------------------------------------------------------------------------------
template <typename T>
struct histogram_intersection_kernel
{
typedef typename T::type scalar_type;
typedef T sample_type;
typedef typename T::mem_manager_type mem_manager_type;
scalar_type operator() (
const sample_type& a,
const sample_type& b
) const
{
scalar_type temp = 0;
for (long i = 0; i < a.size(); ++i)
{
temp += std::min(a(i), b(i));
}
return temp;
}
bool operator== (
const histogram_intersection_kernel&
) const
{
return true;
}
};
template <
typename T
>
void serialize (
const histogram_intersection_kernel<T>& ,
std::ostream&
){}
template <
typename T
>
void deserialize (
histogram_intersection_kernel<T>& ,
std::istream&
){}
// ----------------------------------------------------------------------------------------
template <typename T>

65
dlib/svm/kernel_abstract.h
View File

@ -422,6 +422,71 @@ namespace dlib
provides deserialization support for linear_kernel
!*/
// ----------------------------------------------------------------------------------------
template <
typename T
>
struct histogram_intersection_kernel
{
/*!
REQUIREMENTS ON T
T must be a dlib::matrix object
WHAT THIS OBJECT REPRESENTS
This object represents a histogram intersection kernel kernel
!*/
typedef typename T::type scalar_type;
typedef T sample_type;
typedef typename T::mem_manager_type mem_manager_type;
scalar_type operator() (
const sample_type& a,
const sample_type& b
) const;
/*!
requires
- is_vector(a)
- is_vector(b)
- a.size() == b.size()
- min(a) >= 0
- min(b) >= 0
ensures
- returns sum over all i: std::min(a(i), b(i))
!*/
bool operator== (
const histogram_intersection_kernel& k
) const;
/*!
ensures
- returns true
!*/
};
template <
typename T
>
void serialize (
const histogram_intersection_kernel<T>& item,
std::ostream& out
);
/*!
provides serialization support for histogram_intersection_kernel
!*/
template <
typename T
>
void deserialize (
histogram_intersection_kernel<T>& item,
std::istream& in
);
/*!
provides deserialization support for histogram_intersection_kernel
!*/
// ----------------------------------------------------------------------------------------
template <

63
dlib/svm/sparse_kernel.h
View File

@ -311,6 +311,69 @@ namespace dlib
std::istream& in
){}
// ----------------------------------------------------------------------------------------
template <typename T>
struct sparse_histogram_intersection_kernel
{
typedef typename T::value_type::second_type scalar_type;
typedef T sample_type;
typedef default_memory_manager mem_manager_type;
scalar_type operator() (
const sample_type& a,
const sample_type& b
) const
{
typename sample_type::const_iterator ai = a.begin();
typename sample_type::const_iterator bi = b.begin();
scalar_type sum = 0;
while (ai != a.end() && bi != b.end())
{
if (ai->first == bi->first)
{
sum += std::min(ai->second , bi->second);
++ai;
++bi;
}
else if (ai->first < bi->first)
{
++ai;
}
else
{
++bi;
}
}
return sum;
}
bool operator== (
const sparse_histogram_intersection_kernel&
) const
{
return true;
}
};
template <
typename T
>
void serialize (
const sparse_histogram_intersection_kernel<T>& item,
std::ostream& out
){}
template <
typename T
>
void deserialize (
sparse_histogram_intersection_kernel<T>& item,
std::istream& in
){}
// ----------------------------------------------------------------------------------------
}

82
dlib/svm/sparse_kernel_abstract.h
View File

@ -64,8 +64,8 @@ namespace dlib
) const;
/*!
requires
- a contains a sorted range
- b contains a sorted range
- a is a sparse vector
- b is a sparse vector
ensures
- returns exp(-gamma * sparse_vector::distance_squared(a,b))
!*/
@ -170,8 +170,8 @@ namespace dlib
) const;
/*!
requires
- a contains a sorted range
- b contains a sorted range
- a is a sparse vector
- b is a sparse vector
ensures
- returns tanh(gamma * sparse_vector::dot(a,b) + coef)
!*/
@ -282,8 +282,8 @@ namespace dlib
) const;
/*!
requires
- a contains a sorted range
- b contains a sorted range
- a is a sparse vector
- b is a sparse vector
ensures
- returns pow(gamma * sparse_vector::dot(a,b) + coef, degree)
!*/
@ -359,8 +359,8 @@ namespace dlib
) const;
/*!
requires
- a contains a sorted range
- b contains a sorted range
- a is a sparse vector
- b is a sparse vector
ensures
- returns sparse_vector::dot(a,b)
!*/
@ -396,6 +396,72 @@ namespace dlib
provides deserialization support for sparse_linear_kernel
!*/
// ----------------------------------------------------------------------------------------
template <
typename T
>
struct sparse_histogram_intersection_kernel
{
/*!
REQUIREMENTS ON T
Must be a sparse vector as defined in dlib/svm/sparse_vector_abstract.h
WHAT THIS OBJECT REPRESENTS
This object represents a histogram intersection kernel
that works with sparse vectors.
!*/
typedef typename T::value_type::second_type scalar_type;
typedef T sample_type;
typedef default_memory_manager mem_manager_type;
scalar_type operator() (
const sample_type& a,
const sample_type& b
) const;
/*!
requires
- a is a sparse vector
- b is a sparse vector
- all the values in a and b are >= 0
ensures
- Let A(i) denote the value of the ith dimension of the a vector.
- Let B(i) denote the value of the ith dimension of the b vector.
- returns sum over all i: std::min(A(i), B(i))
!*/
bool operator== (
const sparse_histogram_intersection_kernel& k
) const;
/*!
ensures
- returns true
!*/
};
template <
typename T
>
void serialize (
const sparse_histogram_intersection_kernel<T>& item,
std::ostream& out
);
/*!
provides serialization support for sparse_histogram_intersection_kernel
!*/
template <
typename T
>
void deserialize (
sparse_histogram_intersection_kernel<T>& item,
std::istream& in
);
/*!
provides deserialization support for sparse_histogram_intersection_kernel
!*/
// ----------------------------------------------------------------------------------------
}