详细描述

The Kernel base class.

Non-mathematically spoken, a kernel is a function that given two input objects ${\bf x}$ and ${\bf x'}$ returns a score describing the similarity of the vectors. The score should be larger when the objects are more similar.

It can be defined as

$k({\bf x},{\bf x'})= \Phi_k({\bf x})\cdot \Phi_k({\bf x'})$

where $\Phi$ maps the objects into some potentially high dimensional feature space.

Apart from the input features, the base kernel takes only one argument (the size of the kernel cache) that is used to efficiently train kernel-machines like e.g. SVMs.

In case you would like to define your own kernel, you only have to define a new compute() function (and the kernel name via get_name() and the kernel type get_kernel_type()). A good example to look at is the GaussianKernel.

在文件Kernel.h第150行定义。

继承图，类CKernel

[图例]

所有成员的列表。

公有成员
	CKernel ()
	CKernel (int32_t size)
	CKernel (CFeatures l, CFeatures r, int32_t size)
virtual	~CKernel ()
float64_t	kernel (int32_t idx_a, int32_t idx_b)
void	get_kernel_matrix (float64_t *dst, int32_t m, int32_t *n)
virtual std::vector< float64_t >	get_kernel_col (int32_t j)
virtual std::vector< float64_t >	get_kernel_row (int32_t i)
template<class T >
T *	get_kernel_matrix (int32_t &m, int32_t &n, T *target)
virtual bool	init (CFeatures lhs, CFeatures rhs)
virtual bool	set_normalizer (CKernelNormalizer *normalizer)
virtual CKernelNormalizer *	get_normalizer ()
virtual bool	init_normalizer ()
virtual void	cleanup ()
void	load (CFile *loader)
void	save (CFile *writer)
CFeatures *	get_lhs ()
CFeatures *	get_rhs ()
virtual int32_t	get_num_vec_lhs ()
virtual int32_t	get_num_vec_rhs ()
virtual bool	has_features ()
bool	get_lhs_equals_rhs ()
virtual void	remove_lhs_and_rhs ()
virtual void	remove_lhs ()
virtual void	remove_rhs ()
	takes all necessary steps if the rhs is removed from kernel
virtual EKernelType	get_kernel_type ()=0
virtual EFeatureType	get_feature_type ()=0
virtual EFeatureClass	get_feature_class ()=0
void	set_cache_size (int32_t size)
int32_t	get_cache_size ()
void	list_kernel ()
bool	has_property (EKernelProperty p)
virtual void	clear_normal ()
virtual void	add_to_normal (int32_t vector_idx, float64_t weight)
EOptimizationType	get_optimization_type ()
virtual void	set_optimization_type (EOptimizationType t)
bool	get_is_initialized ()
virtual bool	init_optimization (int32_t count, int32_t IDX, float64_t weights)
virtual bool	delete_optimization ()
bool	init_optimization_svm (CSVM *svm)
virtual float64_t	compute_optimized (int32_t vector_idx)
virtual void	compute_batch (int32_t num_vec, int32_t vec_idx, float64_t target, int32_t num_suppvec, int32_t IDX, float64_t alphas, float64_t factor=1.0)
float64_t	get_combined_kernel_weight ()
void	set_combined_kernel_weight (float64_t nw)
virtual int32_t	get_num_subkernels ()
virtual void	compute_by_subkernel (int32_t vector_idx, float64_t *subkernel_contrib)
virtual const float64_t *	get_subkernel_weights (int32_t &num_weights)
virtual void	set_subkernel_weights (float64_t *weights, int32_t num_weights)
保护成员
void	set_property (EKernelProperty p)
void	unset_property (EKernelProperty p)
void	set_is_initialized (bool p_init)
virtual float64_t	compute (int32_t x, int32_t y)=0
int32_t	compute_row_start (int64_t offs, int32_t n, bool symmetric)
virtual void	load_serializable_post () throw (ShogunException)
virtual void	save_serializable_pre () throw (ShogunException)
virtual void	save_serializable_post () throw (ShogunException)
静态保护成员
template<class T >
static void *	get_kernel_matrix_helper (void *p)
保护属性
int32_t	cache_size
	cache_size in MB
KERNELCACHE_ELEM *	kernel_matrix
CFeatures *	lhs
	feature vectors to occur on left hand side
CFeatures *	rhs
	feature vectors to occur on right hand side
bool	lhs_equals_rhs
	lhs
int32_t	num_lhs
	number of feature vectors on left hand side
int32_t	num_rhs
	number of feature vectors on right hand side
float64_t	combined_kernel_weight
bool	optimization_initialized
EOptimizationType	opt_type
uint64_t	properties
CKernelNormalizer *	normalizer
友元
class	CVarianceKernelNormalizer
class	CSqrtDiagKernelNormalizer
class	CAvgDiagKernelNormalizer
class	CRidgeKernelNormalizer
class	CFirstElementKernelNormalizer
class	CMultitaskKernelNormalizer
class	CMultitaskKernelMklNormalizer
class	CMultitaskKernelMaskNormalizer
class	CMultitaskKernelMaskPairNormalizer
class	CTanimotoKernelNormalizer
class	CDiceKernelNormalizer
class	CZeroMeanCenterKernelNormalizer

构造及析构函数文档

CKernel ( )

default constructor

在文件Kernel.cpp第38行定义。

CKernel ( int32_t size )

constructor

参数:

size	cache size

在文件Kernel.cpp第43行定义。

CKernel	(	CFeatures *	l,
		CFeatures *	r,
		int32_t	size
	)

constructor

参数:

l	features for left-hand side
r	features for right-hand side
size	cache size

在文件Kernel.cpp第54行定义。

~CKernel ( ) [virtual]

在文件Kernel.cpp第67行定义。

成员函数文档

void add_to_normal	(	int32_t	vector_idx,
		float64_t	weight
	)		`[virtual]`

add vector*factor to 'virtual' normal vector

参数:

vector_idx	index
weight	weight

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CLinearKernel、CLinearStringKernel、CWeightedCommWordStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第334行定义。

void cleanup ( ) [virtual]

clean up your kernel

base method only removes lhs and rhs overload to add further cleanup but make sure CKernel::cleanup() is called

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CCustomKernel、CFixedDegreeStringKernel、CGaussianKernel、CGaussianMatchStringKernel、CHistogramWordStringKernel、CLinearKernel、CLinearStringKernel、CLocalAlignmentStringKernel、COligoStringKernel、CPolyKernel、CPolyMatchStringKernel、CPolyMatchWordStringKernel、CPyramidChi2、CSalzbergWordStringKernel、CSigmoidKernel、CSimpleLocalityImprovedStringKernel、CSNPStringKernel、CSparseSpatialSampleStringKernel、CSpectrumMismatchRBFKernel、CSpectrumRBFKernel、CWeightedCommWordStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第162行定义。

void clear_normal ( ) [virtual]

for optimizable kernels, i.e. kernels where the weight vector can be computed explicitly (if it fits into memory)

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CLinearKernel、CLinearStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第339行定义。

virtual float64_t compute	(	int32_t	x,
		int32_t	y
	)		`[protected, pure virtual]`

compute kernel function for features a and b idx_{a,b} denote the index of the feature vectors in the corresponding feature object

abstract base method

参数:

x	index a
y	index b

返回:: computed kernel function at indices a,b

在CAUCKernel、CChi2Kernel、CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CConstKernel、CCustomKernel、CDiagKernel、CDistanceKernel、CDotKernel、CFixedDegreeStringKernel、CGaussianKernel、CGaussianMatchStringKernel、CGaussianShiftKernel、CGaussianShortRealKernel、CHistogramIntersectionKernel、CHistogramWordStringKernel、CLinearStringKernel、CLocalAlignmentStringKernel、CLocalityImprovedStringKernel、CMatchWordStringKernel、COligoStringKernel、CPolyKernel、CPolyMatchStringKernel、CPolyMatchWordStringKernel、CPyramidChi2、CRegulatoryModulesStringKernel、CSalzbergWordStringKernel、CSigmoidKernel、CSimpleLocalityImprovedStringKernel、CSNPStringKernel、CSparseSpatialSampleStringKernel、CSpectrumMismatchRBFKernel、CSpectrumRBFKernel、CTensorProductPairKernel、CWeightedDegreePositionStringKernel、CWeightedDegreeRBFKernel及CWeightedDegreeStringKernel内被实现。

void compute_batch	(	int32_t	num_vec,
		int32_t *	vec_idx,
		float64_t *	target,
		int32_t	num_suppvec,
		int32_t *	IDX,
		float64_t *	alphas,
		float64_t	factor = `1.0`
	)		`[virtual]`

computes output for a batch of examples in an optimized fashion (favorable if kernel supports it, i.e. has KP_BATCHEVALUATION. to the outputvector target (of length num_vec elements) the output for the examples enumerated in vec_idx are added. therefore make sure that it is initialized with ZERO. the following num_suppvec, IDX, alphas arguments are the number of support vectors, their indices and weights

被CCombinedKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第327行定义。

void compute_by_subkernel	(	int32_t	vector_idx,
		float64_t *	subkernel_contrib
	)		`[virtual]`

compute by subkernel

参数:

vector_idx	index
subkernel_contrib	subkernel contribution

被CCombinedKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第349行定义。

float64_t compute_optimized ( int32_t vector_idx ) [virtual]

compute optimized

参数:

vector_idx index to compute

返回:: optimized value at given index

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CLinearKernel、CLinearStringKernel、CWeightedCommWordStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第321行定义。

int32_t compute_row_start	(	int64_t	offs,
		int32_t	n,
		bool	symmetric
	)		`[protected]`

compute row start offset for parallel kernel matrix computation

参数:

offs	offset
n	number of columns
symmetric	whether matrix is symmetric

在文件Kernel.h第673行定义。

bool delete_optimization ( ) [virtual]

delete optimization

返回:: if deleting was successful

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CLinearKernel、CLinearStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第315行定义。

int32_t get_cache_size ( )

return the size of the kernel cache

返回:: size of kernel cache

在文件Kernel.h第502行定义。

float64_t get_combined_kernel_weight ( )

get combined kernel weight

返回:: combined kernel weight

在文件Kernel.h第593行定义。

virtual EFeatureClass get_feature_class ( ) [pure virtual]

return feature class the kernel can deal with

abstract base method

返回:: feature class

在CAUCKernel、CChi2Kernel、CCombinedKernel、CConstKernel、CCustomKernel、CDiagKernel、CDistanceKernel、CDotKernel、CSparseKernel< ST >、CStringKernel< ST >、CTensorProductPairKernel、CWeightedDegreeRBFKernel、CStringKernel< char >、CStringKernel< uint16_t >及CStringKernel< uint64_t >内被实现。

virtual EFeatureType get_feature_type ( ) [pure virtual]

return feature type the kernel can deal with

abstract base method

返回:: feature type

bool get_is_initialized ( )

check if optimization is initialized

返回:: if optimization is initialized

在文件Kernel.h第544行定义。

virtual std::vector<float64_t> get_kernel_col ( int32_t j ) [virtual]

get column j

返回:: the jth column of the kernel matrix

在文件Kernel.h第221行定义。

T* get_kernel_matrix	(	int32_t &	m,
		int32_t &	n,
		T *	target
	)

get kernel matrix real

参数:

m	dimension m of matrix
n	dimension n of matrix
target	the kernel matrix

返回:: the kernel matrix

在文件Kernel.h第264行定义。

void get_kernel_matrix	(	float64_t **	dst,
		int32_t *	m,
		int32_t *	n
	)

get kernel matrix

参数:

dst	destination where matrix will be stored
m	dimension m of matrix
n	dimension n of matrix

在文件Kernel.cpp第78行定义。

static void* get_kernel_matrix_helper ( void * p ) [static, protected]

helper for computing the kernel matrix in a parallel way

参数:

p	thread parameters

在文件Kernel.h第690行定义。

virtual std::vector<float64_t> get_kernel_row ( int32_t i ) [virtual]

get row i

返回:: the ith row of the kernel matrix

在文件Kernel.h第241行定义。

virtual EKernelType get_kernel_type ( ) [pure virtual]

return what type of kernel we are, e.g. Linear,Polynomial, Gaussian,...

abstract base method

返回:: kernel type

在CAUCKernel、CChi2Kernel、CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CConstKernel、CCustomKernel、CDiagKernel、CDistanceKernel、CDotKernel、CFixedDegreeStringKernel、CGaussianKernel、CGaussianMatchStringKernel、CGaussianShiftKernel、CGaussianShortRealKernel、CHistogramIntersectionKernel、CHistogramWordStringKernel、CLinearKernel、CLinearStringKernel、CLocalAlignmentStringKernel、CLocalityImprovedStringKernel、CMatchWordStringKernel、COligoStringKernel、CPolyKernel、CPolyMatchStringKernel、CPolyMatchWordStringKernel、CPyramidChi2、CRegulatoryModulesStringKernel、CSalzbergWordStringKernel、CSigmoidKernel、CSimpleLocalityImprovedStringKernel、CSNPStringKernel、CSparseKernel< ST >、CSparseSpatialSampleStringKernel、CSpectrumMismatchRBFKernel、CSpectrumRBFKernel、CStringKernel< ST >、CTensorProductPairKernel、CWeightedCommWordStringKernel、CWeightedDegreePositionStringKernel、CWeightedDegreeRBFKernel、CWeightedDegreeStringKernel、CStringKernel< char >、CStringKernel< uint16_t >及CStringKernel< uint64_t >内被实现。

CFeatures* get_lhs ( )

get left-hand side of features used in kernel

返回:: features of left-hand side

在文件Kernel.h第410行定义。

bool get_lhs_equals_rhs ( )

test whether features on lhs and rhs are the same

返回:: true if features are the same

在文件Kernel.h第449行定义。

CKernelNormalizer * get_normalizer ( ) [virtual]

obtain the current kernel normalizer

返回:: the kernel normalizer

在文件Kernel.cpp第151行定义。

int32_t get_num_subkernels ( ) [virtual]

get number of subkernels

返回:: number of subkernels

被CCombinedKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第344行定义。

virtual int32_t get_num_vec_lhs ( ) [virtual]

get number of vectors of lhs features

返回:: number of vectors of left-hand side

被CCustomKernel重载。

在文件Kernel.h第422行定义。

virtual int32_t get_num_vec_rhs ( ) [virtual]

get number of vectors of rhs features

返回:: number of vectors of right-hand side

被CCustomKernel重载。

在文件Kernel.h第431行定义。

EOptimizationType get_optimization_type ( )

get optimization type

返回:: optimization type

在文件Kernel.h第532行定义。

CFeatures* get_rhs ( )

get right-hand side of features used in kernel

返回:: features of right-hand side

在文件Kernel.h第416行定义。

const float64_t * get_subkernel_weights ( int32_t & num_weights ) [virtual]

get subkernel weights

参数:

num_weights number of weights will be stored here

返回:: subkernel weights

被CCombinedKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第355行定义。

virtual bool has_features ( ) [virtual]

test whether features have been assigned to lhs and rhs

返回:: true if features are assigned

被CCombinedKernel及CCustomKernel重载。

在文件Kernel.h第440行定义。

bool has_property ( EKernelProperty p )

check if kernel has given property

参数:

p	kernel property

返回:: if kernel has given property

在文件Kernel.h第514行定义。

bool init	(	CFeatures *	lhs,
		CFeatures *	rhs
	)		`[virtual]`

initialize kernel e.g. setup lhs/rhs of kernel, precompute normalization constants etc. make sure to check that your kernel can deal with the supplied features (!)

参数:

lhs	features for left-hand side
rhs	features for right-hand side

返回:: if init was successful

被CAUCKernel、CChi2Kernel、CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CConstKernel、CCustomKernel、CDiagKernel、CDistanceKernel、CDotKernel、CFixedDegreeStringKernel、CGaussianKernel、CGaussianMatchStringKernel、CGaussianShortRealKernel、CHistogramIntersectionKernel、CHistogramWordStringKernel、CLinearKernel、CLinearStringKernel、CLocalAlignmentStringKernel、CLocalityImprovedStringKernel、CMatchWordStringKernel、COligoStringKernel、CPolyKernel、CPolyMatchStringKernel、CPolyMatchWordStringKernel、CPyramidChi2、CRegulatoryModulesStringKernel、CSalzbergWordStringKernel、CSigmoidKernel、CSimpleLocalityImprovedStringKernel、CSNPStringKernel、CSparseKernel< ST >、CSparseSpatialSampleStringKernel、CSpectrumMismatchRBFKernel、CSpectrumRBFKernel、CStringKernel< ST >、CTensorProductPairKernel、CWeightedCommWordStringKernel、CWeightedDegreePositionStringKernel、CWeightedDegreeRBFKernel、CWeightedDegreeStringKernel、CStringKernel< char >、CStringKernel< uint16_t >及CStringKernel< uint64_t >重载。

在文件Kernel.cpp第107行定义。

bool init_normalizer ( ) [virtual]

initialize the current kernel normalizer

返回:: if init was successful

在文件Kernel.cpp第157行定义。

bool init_optimization	(	int32_t	count,
		int32_t *	IDX,
		float64_t *	weights
	)		`[virtual]`

initialize optimization

参数:

count	count
IDX	index
weights	weights

返回:: if initializing was successful

被CCombinedKernel、CCommUlongStringKernel、CCommWordStringKernel、CLinearKernel、CLinearStringKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第308行定义。

bool init_optimization_svm ( CSVM * svm )

initialize optimization

参数:

svm svm model

返回:: if initializing was successful

在文件Kernel.cpp第368行定义。

float64_t kernel	(	int32_t	idx_a,
		int32_t	idx_b
	)

get kernel function for lhs feature vector a and rhs feature vector b

参数:

idx_a	index of feature vector a
idx_b	index of feature vector b

返回:: computed kernel function

在文件Kernel.h第196行定义。

void list_kernel ( )

list kernel

在文件Kernel.cpp第225行定义。

void load ( CFile * loader )

load the kernel matrix

参数:

loader File object via which to load data

在文件Kernel.cpp第169行定义。

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

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.

异常:

ShogunException Will be thrown if an error occurres.

重载CSGObject。

被CGaussianKernel及CWeightedDegreePositionStringKernel重载。

在文件Kernel.cpp第386行定义。

void remove_lhs ( ) [virtual]

remove lhs from kernel

被CCombinedKernel、CCommUlongStringKernel、CSpectrumMismatchRBFKernel、CSpectrumRBFKernel、CWeightedDegreePositionStringKernel及CWeightedDegreeStringKernel重载。

在文件Kernel.cpp第200行定义。

void remove_lhs_and_rhs ( ) [virtual]

remove lhs and rhs from kernel

被CCombinedKernel重载。

在文件Kernel.cpp第185行定义。

void remove_rhs ( ) [virtual]

takes all necessary steps if the rhs is removed from kernel

remove rhs from kernel

被CCombinedKernel及CCommUlongStringKernel重载。

在文件Kernel.cpp第212行定义。

void save ( CFile * writer )

save kernel matrix

参数:

writer File object via which to save data

在文件Kernel.cpp第175行定义。

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

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.

异常:

ShogunException Will be thrown if an error occurres.

重载CSGObject。

在文件Kernel.cpp第401行定义。

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

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.

异常:

ShogunException Will be thrown if an error occurres.

重载CSGObject。

在文件Kernel.cpp第393行定义。

void set_cache_size ( int32_t size )

set the size of the kernel cache

参数: