vnl_crs_index Class Reference

Represents the configuration of a sparse matrix but not the data. More...

#include <vnl_crs_index.h>

List of all members.

Public Types
typedef vcl_pair< int, int >	idx_pair
typedef vcl_vector< idx_pair >	sparse_vector
Public Member Functions
	vnl_crs_index ()
	Constructor - default.
	vnl_crs_index (const vcl_vector< vcl_vector< bool > > &mask)
	Constructor - from a binary mask.
	~vnl_crs_index ()
	Destructor.
int	num_rows () const
	number of rows in the sparse matrix.
int	num_cols () const
	number of columns in the sparse matrix.
int	num_non_zero () const
	number of non-zero elements.
sparse_vector	sparse_row (int i) const
	returns row i as a vector of index-column pairs.
sparse_vector	sparse_col (int j) const
	returns column j as a vector of index-row pairs.
int	operator() (int i, int j) const
	return the index at location (i,j).
Private Attributes
unsigned int	num_cols_
	The number of columns in the matrix.
vcl_vector< int >	col_idx_
	The column for each non-zero element.
vcl_vector< int >	row_ptr_
	The index of the first non-zero element in each row.

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Detailed Description

Represents the configuration of a sparse matrix but not the data.

This is essentially a sparse matrix of indices into a data vector Compressed row storage is used for representation This class is useful when working with several sparse matrices that share a common sparse structure.

Definition at line 26 of file vnl_crs_index.h.

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Member Typedef Documentation

typedef vcl_pair<int,int> vnl_crs_index::idx_pair

Definition at line 29 of file vnl_crs_index.h.

typedef vcl_vector<idx_pair> vnl_crs_index::sparse_vector

Definition at line 30 of file vnl_crs_index.h.

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Constructor & Destructor Documentation

vnl_crs_index::vnl_crs_index

(

)

[inline]

Constructor - default.

Definition at line 33 of file vnl_crs_index.h.

vnl_crs_index::vnl_crs_index

(

const vcl_vector< vcl_vector< bool > > &

mask

)

Constructor - from a binary mask.

Definition at line 13 of file vnl_crs_index.cxx.

vnl_crs_index::~vnl_crs_index

(

)

[inline]

Destructor.

Definition at line 39 of file vnl_crs_index.h.

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Member Function Documentation

int vnl_crs_index::num_cols

(

)

const [inline]

number of columns in the sparse matrix.

Definition at line 45 of file vnl_crs_index.h.

int vnl_crs_index::num_non_zero

(

)

const [inline]

number of non-zero elements.

Definition at line 48 of file vnl_crs_index.h.

int vnl_crs_index::num_rows

(

)

const [inline]

number of rows in the sparse matrix.

Definition at line 42 of file vnl_crs_index.h.

int vnl_crs_index::operator()	(	int	i,
		int	j
	)		const

return the index at location (i,j).

returns -1 if the entry is 0

Definition at line 34 of file vnl_crs_index.cxx.

vnl_crs_index::sparse_vector vnl_crs_index::sparse_col

(

int

j

)

const

returns column j as a vector of index-row pairs.

Note:

because of CRS this method is a bit less efficient than sparse_row

Definition at line 72 of file vnl_crs_index.cxx.

vnl_crs_index::sparse_vector vnl_crs_index::sparse_row

(

int

i

)

const

returns row i as a vector of index-column pairs.

Definition at line 59 of file vnl_crs_index.cxx.

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Member Data Documentation

vcl_vector<int> vnl_crs_index::col_idx_ [private]

The column for each non-zero element.

Definition at line 65 of file vnl_crs_index.h.

unsigned int vnl_crs_index::num_cols_ [private]

The number of columns in the matrix.

Definition at line 63 of file vnl_crs_index.h.

vcl_vector<int> vnl_crs_index::row_ptr_ [private]

The index of the first non-zero element in each row.

Definition at line 67 of file vnl_crs_index.h.

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

• core/vnl/vnl_crs_index.h
• core/vnl/vnl_crs_index.cxx