#include <core.hpp>

Inheritance diagram for cv::SparseMat:

Classes
struct	Hdr
	the sparse matrix header More...

struct	Node
	sparse matrix node - element of a hash table More...

Public Types
enum	{ MAGIC_VAL =0x42FD0000, MAX_DIM =CV_MAX_DIM, HASH_SCALE =0x5bd1e995, HASH_BIT =0x80000000 }

typedef SparseMatIterator	iterator

typedef SparseMatConstIterator	const_iterator

Public Member Functions
	SparseMat ()
	default constructor More...

	SparseMat (int dims, const int *_sizes, int _type)
	creates matrix of the specified size and type More...

	SparseMat (const SparseMat &m)
	copy constructor More...

	SparseMat (const Mat &m)
	converts dense 2d matrix to the sparse form More...

	SparseMat (const CvSparseMat *m)
	converts old-style sparse matrix to the new-style. All the data is copied More...

	~SparseMat ()
	the destructor More...

SparseMat &	operator= (const SparseMat &m)
	assignment operator. This is O(1) operation, i.e. no data is copied More...

SparseMat &	operator= (const Mat &m)
	equivalent to the corresponding constructor More...

SparseMat	clone () const
	creates full copy of the matrix More...

void	copyTo (SparseMat &m) const
	copies all the data to the destination matrix. All the previous content of m is erased More...

void	copyTo (Mat &m) const
	converts sparse matrix to dense matrix. More...

void	convertTo (SparseMat &m, int rtype, double alpha=1) const
	multiplies all the matrix elements by the specified scale factor alpha and converts the results to the specified data type More...

void	convertTo (Mat &m, int rtype, double alpha=1, double beta=0) const
	converts sparse matrix to dense n-dim matrix with optional type conversion and scaling. More...

void	assignTo (SparseMat &m, int type=-1) const

void	create (int dims, const int *_sizes, int _type)
	reallocates sparse matrix. More...

void	clear ()
	sets all the sparse matrix elements to 0, which means clearing the hash table. More...

void	addref ()
	manually increments the reference counter to the header. More...

void	release ()

	operator CvSparseMat * () const
	converts sparse matrix to the old-style representation; all the elements are copied. More...

size_t	elemSize () const
	returns the size of each element in bytes (not including the overhead - the space occupied by SparseMat::Node elements) More...

size_t	elemSize1 () const
	returns elemSize()/channels() More...

int	type () const
	returns type of sparse matrix elements More...

int	depth () const
	returns the depth of sparse matrix elements More...

int	channels () const
	returns the number of channels More...

const int *	size () const
	returns the array of sizes, or NULL if the matrix is not allocated More...

int	size (int i) const
	returns the size of i-th matrix dimension (or 0) More...

int	dims () const
	returns the matrix dimensionality More...

size_t	nzcount () const
	returns the number of non-zero elements (=the number of hash table nodes) More...

size_t	hash (int i0) const
	computes the element hash value (1D case) More...

size_t	hash (int i0, int i1) const
	computes the element hash value (2D case) More...

size_t	hash (int i0, int i1, int i2) const
	computes the element hash value (3D case) More...

size_t	hash (const int *idx) const
	computes the element hash value (nD case) More...

SparseMatIterator	end ()
	returns the sparse matrix iterator at the matrix end More...

SparseMatConstIterator	end () const
	returns the read-only sparse matrix iterator at the matrix end More...

template<typename _Tp >
SparseMatIterator_< _Tp >	end ()
	returns the typed sparse matrix iterator at the matrix end More...

template<typename _Tp >
SparseMatConstIterator_< _Tp >	end () const
	returns the typed read-only sparse matrix iterator at the matrix end More...

template<typename _Tp >
_Tp &	value (Node *n)
	returns the value stored in the sparse martix node More...

template<typename _Tp >
const _Tp &	value (const Node *n) const
	returns the value stored in the sparse martix node More...

Node *	node (size_t nidx)

const Node *	node (size_t nidx) const

uchar *	newNode (const int *idx, size_t hashval)

void	removeNode (size_t hidx, size_t nidx, size_t previdx)

void	resizeHashTab (size_t newsize)


uchar *	ptr (int i0, bool createMissing, size_t *hashval=0)
	returns pointer to the specified element (1D case) More...

uchar *	ptr (int i0, int i1, bool createMissing, size_t *hashval=0)
	returns pointer to the specified element (2D case) More...

uchar *	ptr (int i0, int i1, int i2, bool createMissing, size_t *hashval=0)
	returns pointer to the specified element (3D case) More...

uchar *	ptr (const int idx, bool createMissing, size_t hashval=0)
	returns pointer to the specified element (nD case) More...


template<typename _Tp >
_Tp &	ref (int i0, size_t *hashval=0)
	returns reference to the specified element (1D case) More...

template<typename _Tp >
_Tp &	ref (int i0, int i1, size_t *hashval=0)
	returns reference to the specified element (2D case) More...

template<typename _Tp >
_Tp &	ref (int i0, int i1, int i2, size_t *hashval=0)
	returns reference to the specified element (3D case) More...

template<typename _Tp >
_Tp &	ref (const int idx, size_t hashval=0)
	returns reference to the specified element (nD case) More...


template<typename _Tp >
_Tp	value (int i0, size_t *hashval=0) const
	returns value of the specified element (1D case) More...

template<typename _Tp >
_Tp	value (int i0, int i1, size_t *hashval=0) const
	returns value of the specified element (2D case) More...

template<typename _Tp >
_Tp	value (int i0, int i1, int i2, size_t *hashval=0) const
	returns value of the specified element (3D case) More...

template<typename _Tp >
_Tp	value (const int idx, size_t hashval=0) const
	returns value of the specified element (nD case) More...


template<typename _Tp >
const _Tp *	find (int i0, size_t *hashval=0) const
	returns pointer to the specified element (1D case) More...

template<typename _Tp >
const _Tp *	find (int i0, int i1, size_t *hashval=0) const
	returns pointer to the specified element (2D case) More...

template<typename _Tp >
const _Tp *	find (int i0, int i1, int i2, size_t *hashval=0) const
	returns pointer to the specified element (3D case) More...

template<typename _Tp >
const _Tp *	find (const int idx, size_t hashval=0) const
	returns pointer to the specified element (nD case) More...

void	erase (int i0, int i1, size_t *hashval=0)
	erases the specified element (2D case) More...

void	erase (int i0, int i1, int i2, size_t *hashval=0)
	erases the specified element (3D case) More...

void	erase (const int idx, size_t hashval=0)
	erases the specified element (nD case) More...

SparseMatIterator	begin ()
	returns the sparse matrix iterator at the matrix beginning More...

template<typename _Tp >
SparseMatIterator_< _Tp >	begin ()
	returns the sparse matrix iterator at the matrix beginning More...

SparseMatConstIterator	begin () const
	returns the read-only sparse matrix iterator at the matrix beginning More...

template<typename _Tp >
SparseMatConstIterator_< _Tp >	begin () const
	returns the read-only sparse matrix iterator at the matrix beginning More...

Public Attributes
int	flags

Hdr *	hdr

Detailed Description

Sparse matrix class.

The class represents multi-dimensional sparse numerical arrays. Such a sparse array can store elements of any type that cv::Mat is able to store. "Sparse" means that only non-zero elements are stored (though, as a result of some operations on a sparse matrix, some of its stored elements can actually become 0. It's user responsibility to detect such elements and delete them using cv::SparseMat::erase(). The non-zero elements are stored in a hash table that grows when it's filled enough, so that the search time remains O(1) in average. Elements can be accessed using the following methods:

Query operations: cv::SparseMat::ptr() and the higher-level cv::SparseMat::ref(), cv::SparseMat::value() and cv::SparseMat::find, for example:
const int dims = 5;
int size[] = {10, 10, 10, 10, 10};
SparseMat sparse_mat(dims, size, CV_32F);
for(int i = 0; i < 1000; i++)
{
int idx[dims];
for(int k = 0; k < dims; k++)
idx[k] = rand()%sparse_mat.size(k);
sparse_mat.ref<float>(idx) += 1.f;
}
Sparse matrix iterators. Like cv::Mat iterators and unlike cv::Mat iterators, the sparse matrix iterators are STL-style, that is, the iteration is done as following:
// prints elements of a sparse floating-point matrix and the sum of elements.
SparseMatConstIterator_<float>
it = sparse_mat.begin<float>(),
it_end = sparse_mat.end<float>();
double s = 0;
int dims = sparse_mat.dims();
for(; it != it_end; ++it)
{
// print element indices and the element value
const Node* n = it.node();
printf("(")
for(int i = 0; i < dims; i++)
printf("%3d%c", n->idx[i], i < dims-1 ? ',' : ')');
printf(": %f\n", *it);
s += *it;
}
printf("Element sum is %g\n", s);
If you run this loop, you will notice that elements are enumerated in no any logical order (lexicographical etc.), they come in the same order as they stored in the hash table, i.e. semi-randomly.

You may collect pointers to the nodes and sort them to get the proper ordering. Note, however, that pointers to the nodes may become invalid when you add more elements to the matrix; this is because of possible buffer reallocation.
A combination of the above 2 methods when you need to process 2 or more sparse matrices simultaneously, e.g. this is how you can compute unnormalized cross-correlation of the 2 floating-point sparse matrices:
double crossCorr(const SparseMat& a, const SparseMat& b)
{
const SparseMat *_a = &a, *_b = &b;
// if b contains less elements than a,
// it's faster to iterate through b
if(_a->nzcount() > _b->nzcount())
std::swap(_a, _b);
SparseMatConstIterator_<float> it = _a->begin<float>(),
it_end = _a->end<float>();
double ccorr = 0;
for(; it != it_end; ++it)
{
// take the next element from the first matrix
float avalue = *it;
const Node* anode = it.node();
// and try to find element with the same index in the second matrix.
// since the hash value depends only on the element index,
// we reuse hashvalue stored in the node
float bvalue = _b->value<float>(anode->idx,&anode->hashval);
ccorr += avalue*bvalue;
}
return ccorr;
}

Member Typedef Documentation

typedef SparseMatConstIterator cv::SparseMat::const_iterator

typedef SparseMatIterator cv::SparseMat::iterator

Member Enumeration Documentation

anonymous enum

Enumerator
MAGIC_VAL
MAX_DIM
HASH_SCALE
HASH_BIT

Constructor & Destructor Documentation

cv::SparseMat::SparseMat ( )

inline

default constructor

cv::SparseMat::SparseMat	(	int	dims,
		const int *	_sizes,
		int	_type
	)

inline

creates matrix of the specified size and type

cv::SparseMat::SparseMat ( const SparseMat & m )

inline

copy constructor

cv::SparseMat::SparseMat ( const Mat & m )

explicit

converts dense 2d matrix to the sparse form

Parameters

m	the input matrix

cv::SparseMat::SparseMat ( const CvSparseMat * m )

converts old-style sparse matrix to the new-style. All the data is copied

cv::SparseMat::~SparseMat ( )

inline

the destructor

Member Function Documentation

void cv::SparseMat::addref ( )

inline

manually increments the reference counter to the header.

void cv::SparseMat::assignTo	(	SparseMat &	m,
		int	type = `-1`
	)		const

inline

SparseMatIterator cv::SparseMat::begin ( )

inline

returns the sparse matrix iterator at the matrix beginning

return the sparse matrix iterator pointing to the first sparse matrix element

template<typename _Tp >

SparseMatIterator_< _Tp > cv::SparseMat::begin ( )

inline

returns the sparse matrix iterator at the matrix beginning

SparseMatConstIterator cv::SparseMat::begin ( ) const

inline

returns the read-only sparse matrix iterator at the matrix beginning

template<typename _Tp >

SparseMatConstIterator_< _Tp > cv::SparseMat::begin ( ) const

inline

returns the read-only sparse matrix iterator at the matrix beginning

int cv::SparseMat::channels ( ) const

inline

returns the number of channels

void cv::SparseMat::clear ( )

sets all the sparse matrix elements to 0, which means clearing the hash table.

SparseMat cv::SparseMat::clone ( ) const

inline

creates full copy of the matrix

void cv::SparseMat::convertTo	(	SparseMat &	m,
		int	rtype,
		double	alpha = `1`
	)		const

multiplies all the matrix elements by the specified scale factor alpha and converts the results to the specified data type

void cv::SparseMat::convertTo	(	Mat &	m,
		int	rtype,
		double	alpha = `1`,
		double	beta = `0`
	)		const

converts sparse matrix to dense n-dim matrix with optional type conversion and scaling.

Parameters

m	Destination matrix
rtype	The output matrix data type. When it is =-1, the output array will have the same data type as (*this)
alpha	The scale factor
beta	The optional delta added to the scaled values before the conversion

void cv::SparseMat::copyTo ( SparseMat & m ) const

copies all the data to the destination matrix. All the previous content of m is erased

void cv::SparseMat::copyTo ( Mat & m ) const

converts sparse matrix to dense matrix.

void cv::SparseMat::create	(	int	dims,
		const int *	_sizes,
		int	_type
	)

reallocates sparse matrix.

If the matrix already had the proper size and type, it is simply cleared with clear(), otherwise, the old matrix is released (using release()) and the new one is allocated.

int cv::SparseMat::depth ( ) const

inline

returns the depth of sparse matrix elements

int cv::SparseMat::dims ( ) const

inline

returns the matrix dimensionality

size_t cv::SparseMat::elemSize ( ) const

inline

returns the size of each element in bytes (not including the overhead - the space occupied by SparseMat::Node elements)

size_t cv::SparseMat::elemSize1 ( ) const

inline

returns elemSize()/channels()

SparseMatIterator cv::SparseMat::end ( )

inline

returns the sparse matrix iterator at the matrix end

return the sparse matrix iterator pointing to the element following the last sparse matrix element

SparseMatConstIterator cv::SparseMat::end ( ) const

inline

returns the read-only sparse matrix iterator at the matrix end

template<typename _Tp >

SparseMatIterator_< _Tp > cv::SparseMat::end ( )

inline

returns the typed sparse matrix iterator at the matrix end

template<typename _Tp >

SparseMatConstIterator_< _Tp > cv::SparseMat::end ( ) const

inline

returns the typed read-only sparse matrix iterator at the matrix end

void cv::SparseMat::erase	(	int	i0,
		int	i1,
		size_t *	hashval = `0`
	)

erases the specified element (2D case)

void cv::SparseMat::erase	(	int	i0,
		int	i1,
		int	i2,
		size_t *	hashval = `0`
	)

erases the specified element (3D case)

void cv::SparseMat::erase	(	const int *	idx,
		size_t *	hashval = `0`
	)

erases the specified element (nD case)

template<typename _Tp >

const _Tp * cv::SparseMat::find	(	int	i0,
		size_t *	hashval = `0`
	)		const

inline

returns pointer to the specified element (1D case)

Return pointer to the specified sparse matrix element if it exists

find<_Tp>(i0,...[,hashval]) is equivalent to (_const Tp*)ptr(i0,...false[,hashval]).

If the specified element does not exist, the methods return NULL.

template<typename _Tp >

const _Tp * cv::SparseMat::find	(	int	i0,
		int	i1,
		size_t *	hashval = `0`
	)		const

inline

returns pointer to the specified element (2D case)

template<typename _Tp >

const _Tp * cv::SparseMat::find	(	int	i0,
		int	i1,
		int	i2,
		size_t *	hashval = `0`
	)		const

inline

returns pointer to the specified element (3D case)

template<typename _Tp >

const _Tp * cv::SparseMat::find	(	const int *	idx,
		size_t *	hashval = `0`
	)		const

inline

returns pointer to the specified element (nD case)

size_t cv::SparseMat::hash ( int i0 ) const

inline

computes the element hash value (1D case)

size_t cv::SparseMat::hash	(	int	i0,
		int	i1
	)		const

inline

computes the element hash value (2D case)

size_t cv::SparseMat::hash	(	int	i0,
		int	i1,
		int	i2
	)		const

inline

computes the element hash value (3D case)

size_t cv::SparseMat::hash ( const int * idx ) const

inline

computes the element hash value (nD case)

uchar* cv::SparseMat::newNode	(	const int *	idx,
		size_t	hashval
	)

SparseMat::Node * cv::SparseMat::node ( size_t nidx )

inline

const SparseMat::Node * cv::SparseMat::node ( size_t nidx ) const

inline

size_t cv::SparseMat::nzcount ( ) const

inline

returns the number of non-zero elements (=the number of hash table nodes)

cv::SparseMat::operator CvSparseMat * ( ) const

converts sparse matrix to the old-style representation; all the elements are copied.

SparseMat & cv::SparseMat::operator= ( const SparseMat & m )

inline

assignment operator. This is O(1) operation, i.e. no data is copied

SparseMat & cv::SparseMat::operator= ( const Mat & m )

inline

equivalent to the corresponding constructor

uchar* cv::SparseMat::ptr	(	int	i0,
		bool	createMissing,
		size_t *	hashval = `0`
	)

returns pointer to the specified element (1D case)

specialized variants for 1D, 2D, 3D cases and the generic_type one for n-D case.

return pointer to the matrix element.

if the element is there (it's non-zero), the pointer to it is returned
if it's not there and createMissing=false, NULL pointer is returned
if it's not there and createMissing=true, then the new element is created and initialized with 0. Pointer to it is returned
if the optional hashval pointer is not NULL, the element hash value is not computed, but *hashval is taken instead.

uchar* cv::SparseMat::ptr	(	int	i0,
		int	i1,
		bool	createMissing,
		size_t *	hashval = `0`
	)

returns pointer to the specified element (2D case)

uchar* cv::SparseMat::ptr	(	int	i0,
		int	i1,
		int	i2,
		bool	createMissing,
		size_t *	hashval = `0`
	)

returns pointer to the specified element (3D case)

uchar* cv::SparseMat::ptr	(	const int *	idx,
		bool	createMissing,
		size_t *	hashval = `0`
	)

returns pointer to the specified element (nD case)

template<typename _Tp >

_Tp & cv::SparseMat::ref	(	int	i0,
		size_t *	hashval = `0`
	)

inline

returns reference to the specified element (1D case)

return read-write reference to the specified sparse matrix element.

ref<_Tp>(i0,...[,hashval]) is equivalent to *(_Tp*)ptr(i0,...,true[,hashval]). The methods always return a valid reference. If the element did not exist, it is created and initialiazed with 0.

template<typename _Tp >

_Tp & cv::SparseMat::ref	(	int	i0,
		int	i1,
		size_t *	hashval = `0`
	)

inline

returns reference to the specified element (2D case)

template<typename _Tp >

_Tp & cv::SparseMat::ref	(	int	i0,
		int	i1,
		int	i2,
		size_t *	hashval = `0`
	)

inline

returns reference to the specified element (3D case)

template<typename _Tp >

_Tp & cv::SparseMat::ref	(	const int *	idx,
		size_t *	hashval = `0`
	)

inline

returns reference to the specified element (nD case)

void cv::SparseMat::release ( )

inline

void cv::SparseMat::removeNode	(	size_t	hidx,
		size_t	nidx,
		size_t	previdx
	)

void cv::SparseMat::resizeHashTab ( size_t newsize )

const int * cv::SparseMat::size ( ) const

inline

returns the array of sizes, or NULL if the matrix is not allocated

int cv::SparseMat::size ( int i ) const

inline

returns the size of i-th matrix dimension (or 0)

int cv::SparseMat::type ( ) const

inline

returns type of sparse matrix elements

template<typename _Tp >

_Tp cv::SparseMat::value	(	int	i0,
		size_t *	hashval = `0`
	)		const

inline

returns value of the specified element (1D case)

return value of the specified sparse matrix element.

value<_Tp>(i0,...[,hashval]) is equivalent

{ const _Tp* p = find<_Tp>(i0,...[,hashval]); return p ? *p : _Tp(); }

That is, if the element did not exist, the methods return 0.

template<typename _Tp >

_Tp cv::SparseMat::value	(	int	i0,
		int	i1,
		size_t *	hashval = `0`
	)		const

inline

returns value of the specified element (2D case)

template<typename _Tp >

_Tp cv::SparseMat::value	(	int	i0,
		int	i1,
		int	i2,
		size_t *	hashval = `0`
	)		const

inline

returns value of the specified element (3D case)

template<typename _Tp >

_Tp cv::SparseMat::value	(	const int *	idx,
		size_t *	hashval = `0`
	)		const

inline

returns value of the specified element (nD case)

template<typename _Tp >

_Tp & cv::SparseMat::value ( Node * n )

inline

returns the value stored in the sparse martix node

template<typename _Tp >

const _Tp & cv::SparseMat::value ( const Node * n ) const

inline

returns the value stored in the sparse martix node

Member Data Documentation

int cv::SparseMat::flags

Hdr* cv::SparseMat::hdr

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

Classes

Public Types

Public Member Functions

Public Attributes

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation