SparseBooleanMatrix Class Reference

Sparse representation of a boolean matrix, using HashSets. More...

Inheritance diagram for SparseBooleanMatrix:

List of all members.

Public Member Functions
IMatrix< bool >	CreateMatrix (int x, int y)
	Create a matrix with a given number of rows and columns.
IList< int >	GetEntriesByColumn (int column_id)
IList< int >	GetEntriesByRow (int row_id)
	Get all true entries (column IDs) of a row.
int	NumEntriesByColumn (int column_id)
	Get all the number of entries in a column.
int	NumEntriesByRow (int row_id)
	Get all the number of entries in a row.
int	Overlap (IBooleanMatrix s)
	Get the overlap of two matrices, i.e. the number of true entries where they agree.
void	Resize (int num_rows, int num_cols)
	Grows or shrinks the matrix to the requested size, if necessary.
IMatrix< bool >	Transpose ()
	Get the transpose of the matrix, i.e. a matrix where rows and columns are interchanged.
Protected Attributes
internal IList< ISet< int > >	row_list = new List<ISet<int>>()
	internal data representation: list of sets representing the rows
Properties
virtual bool	IsSymmetric [get]
	True if the matrix is stored in a symmetric manner, false otherwise.
IList< int >	NonEmptyColumnIDs [get]
IList< int >	NonEmptyRowIDs [get]
	The IDs of the non-empty rows in the matrix (the ones that contain at least one true entry)
int	NumberOfColumns [get]
	The number of columns in the matrix.
int	NumberOfEntries [get]
	The number of (true) entries.
int	NumberOfRows [get]
	The number of rows in the matrix.
bool	this[int x, int y] [get, set]
	Indexer to access the elements of the matrix.
ICollection< int >	this[int x] [get]
	Indexer to access the rows of the matrix.

---

Detailed Description

Sparse representation of a boolean matrix, using HashSets.

Fast row-wise access is possible. Indexes are zero-based.

---

Member Function Documentation

IMatrix<bool> CreateMatrix	(	int	num_rows,
		int	num_columns
	)		[inline]

Create a matrix with a given number of rows and columns.

Parameters:

num_rows	the number of rows
num_columns	the number of columns

Returns:

A matrix with num_rows rows and num_column columns

Implements IMatrix< T >.

IList<int> GetEntriesByColumn

(

int

column_id

)

[inline]

Takes O(N) worst-case time, where N is the number of rows, if the internal hash table can be queried in constant time.

Implements IBooleanMatrix.

IList<int> GetEntriesByRow

(

int

row_id

)

[inline]

Get all true entries (column IDs) of a row.

Parameters:

row_id

the row ID

Returns:

a list of column IDs

Implements IBooleanMatrix.

int NumEntriesByColumn

(

int

column_id

)

[inline]

Get all the number of entries in a column.

Parameters:

column_id

the column ID

Returns:

the number of entries in column column_id

Implements IBooleanMatrix.

int NumEntriesByRow

(

int

row_id

)

[inline]

Get all the number of entries in a row.

Parameters:

row_id

the row ID

Returns:

the number of entries in row row_id

Implements IBooleanMatrix.

int Overlap

(

IBooleanMatrix

s

)

[inline]

Get the overlap of two matrices, i.e. the number of true entries where they agree.

Parameters:

s	the SparseBooleanMatrix to compare to

Returns:

the number of entries that are true in both matrices

Implements IBooleanMatrix.

void Resize	(	int	num_rows,
		int	num_cols
	)		[inline]

Grows or shrinks the matrix to the requested size, if necessary.

The new entries are filled with zeros. Obsolete entries are removed.

Parameters:

num_rows	the number of rows
num_cols	the number of columns

Implements IMatrix< T >.

IMatrix<bool> Transpose

(

)

[inline]

Get the transpose of the matrix, i.e. a matrix where rows and columns are interchanged.

Returns:

the transpose of the matrix (copy)

Implements IMatrix< T >.

---

Member Data Documentation

internal IList<ISet<int> > row_list = new List<ISet<int>>() [protected]

internal data representation: list of sets representing the rows

---

Property Documentation

virtual bool IsSymmetric [get]

True if the matrix is stored in a symmetric manner, false otherwise.

Also true for skew symmetric matrices that exploit this property in order to save memory

Implements IMatrix< T >.

IList<int> NonEmptyColumnIDs [get]

iterates over the complete data structure

Implements IBooleanMatrix.

IList<int> NonEmptyRowIDs [get]

The IDs of the non-empty rows in the matrix (the ones that contain at least one true entry)

Implements IBooleanMatrix.

int NumberOfColumns [get]

The number of columns in the matrix.

The number of columns in the matrix

Implements IMatrix< T >.

int NumberOfEntries [get]

The number of (true) entries.

Implements IBooleanMatrix.

int NumberOfRows [get]

The number of rows in the matrix.

The number of rows in the matrix

Implements IMatrix< T >.

bool this[int x, int y] [get, set]

Indexer to access the elements of the matrix.

Parameters:

x	the row ID
y	the column ID

Implements IMatrix< T >.

ICollection<int> this[int x] [get]

Indexer to access the rows of the matrix.

Parameters:

x	the row ID

Implements IBooleanMatrix.

---

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

• SparseBooleanMatrix.cs