Jaccard Class Reference

Class for storing and computing the Jaccard index (Tanimoto coefficient) More...

Inheritance diagram for Jaccard:

List of all members.

Public Member Functions
void	AddEntity (int entity_id)
	Add an entity to the ICorrelationMatrix by growing it to the requested size.
float	ComputeCorrelation (ICollection< int > vector_i, ICollection< int > vector_j)
	Computes the correlation of two binary vectors.
void	ComputeCorrelations (IBooleanMatrix entity_data)
	Compute the correlations from an implicit feedback, positive-only dataset.
override IMatrix< T >	CreateMatrix (int num_rows, int num_columns)
	Create a matrix with a given number of rows and columns.
	Jaccard (int num_entities)
	Creates an object of type Jaccard.
override void	Resize (int size)
	Resize to the given size.
void	Resize (int num_rows, int num_cols)
	Grows or shrinks the matrix to the requested size, if necessary.
	SparseMatrix (int num_rows, int num_cols)
	Create a sparse matrix with a given number of rows.
	SymmetricSparseMatrix (int dimension)
	Create a symmetric sparse matrix with a given dimension.
virtual IMatrix< T >	Transpose ()
	Get the transpose of the matrix, i.e. a matrix where rows and columns are interchanged.
void	Write (StreamWriter writer)
	Write out the correlations to a StreamWriter.
Protected Member Functions
override float	ComputeCorrelationFromOverlap (float overlap, float count_x, float count_y)
Protected Attributes
internal List< List< int > >	index_list = new List<List<int>>()
	List of lists that stores the column indices of the entries.
internal List< List< T > >	value_list = new List<List<T>>()
	List of lists that stores the values of the entries.
Properties
override bool	IsSymmetric [get]
	returns true if the matrix is symmetric, which is generally the case for similarity matrices
override IList< Tuple< int, int > >	NonEmptyEntryIDs [get]
	The row and column IDs of non-empty entries in the matrix.
int	NumberOfColumns [get, set]
	The number of columns of the matrix.
override int	NumberOfNonEmptyEntries [get]
	The number of non-empty entries in the matrix.
int	NumberOfRows [get]
	The number of rows of the matrix.
int	NumEntities [get, set]
	Number of entities the correlation is defined over.
override T	this[int x, int y] [get, set]
	Access the elements of the sparse matrix.
Dictionary< int, T >	this[int x] [get]
	Get a row of the matrix.
bool	Weighted [get, set]
	If set to true, give a lower weight to evidence coming from very frequent entities.

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Detailed Description

Class for storing and computing the Jaccard index (Tanimoto coefficient)

The Jaccard index is often also called the Tanimoto coefficient.

http://en.wikipedia.org/wiki/Jaccard_index

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Constructor & Destructor Documentation

Jaccard

(

int

num_entities

)

[inline]

Creates an object of type Jaccard.

Parameters:

num_entities

the number of entities

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Member Function Documentation

void AddEntity

(

int

entity_id

)

[inline, inherited]

Add an entity to the ICorrelationMatrix by growing it to the requested size.

Note that you still have to correctly compute and set the entity's correlation values

Parameters:

entity_id

the numerical ID of the entity

Implements ICorrelationMatrix.

float ComputeCorrelation	(	ICollection< int >	vector_i,
		ICollection< int >	vector_j
	)		[inline, inherited]

Computes the correlation of two binary vectors.

Parameters:

vector_i	the first vector
vector_j	the second vector

Returns:

the correlation of the two vectors

Implements IBinaryDataCorrelationMatrix.

void ComputeCorrelations

(

IBooleanMatrix

entity_data

)

[inline, inherited]

Compute the correlations from an implicit feedback, positive-only dataset.

Parameters:

entity_data

the implicit feedback set, rows contain the entities to correlate

Implements IBinaryDataCorrelationMatrix.

override IMatrix<T> CreateMatrix	(	int	num_rows,
		int	num_columns
	)		[inline, virtual, inherited]

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

Reimplemented from SparseMatrix< T >.

Reimplemented in SkewSymmetricSparseMatrix.

override void Resize

(

int

size

)

[inline, inherited]

Resize to the given size.

Parameters:

size

the size

Implements ICorrelationMatrix.

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

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 >.

SparseMatrix	(	int	num_rows,
		int	num_cols
	)		[inline, inherited]

Create a sparse matrix with a given number of rows.

Parameters:

num_rows	the number of rows
num_cols	the number of columns

SymmetricSparseMatrix

(

int

dimension

)

[inline, inherited]

Create a symmetric sparse matrix with a given dimension.

Parameters:

dimension

the dimension (number of rows/columns)

virtual IMatrix<T> Transpose

(

)

[inline, virtual, inherited]

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 >.

void Write

(

StreamWriter

writer

)

[inline, inherited]

Write out the correlations to a StreamWriter.

Parameters:

writer

A StreamWriter

Implements ICorrelationMatrix.

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Member Data Documentation

internal List<List<int> > index_list = new List<List<int>>() [protected, inherited]

List of lists that stores the column indices of the entries.

internal List<List<T> > value_list = new List<List<T>>() [protected, inherited]

List of lists that stores the values of the entries.

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Property Documentation

override IList<Tuple<int, int> > NonEmptyEntryIDs [get, inherited]

The row and column IDs of non-empty entries in the matrix.

The row and column IDs of non-empty entries in the matrix

Reimplemented from SparseMatrix< T >.

int NumberOfColumns [get, set, inherited]

The number of columns of the matrix.

The number of columns of the matrix

Implements IMatrix< T >.

override int NumberOfNonEmptyEntries [get, inherited]

The number of non-empty entries in the matrix.

The number of non-empty entries in the matrix

Reimplemented from SparseMatrix< T >.

int NumberOfRows [get, inherited]

The number of rows of the matrix.

The number of rows of the matrix

Implements IMatrix< T >.

int NumEntities [get, set, inherited]

Number of entities the correlation is defined over.

Implements ICorrelationMatrix.

override T this[int x, int y] [get, set, inherited]

Access the elements of the sparse matrix.

Parameters:

x	the row ID
y	the column ID

Reimplemented from SparseMatrix< T >.

Reimplemented in SkewSymmetricSparseMatrix.

Dictionary<int, T> this[int x] [get, inherited]

Get a row of the matrix.

Parameters:

x	the row ID

bool Weighted [get, set, inherited]

If set to true, give a lower weight to evidence coming from very frequent entities.

Implements IBinaryDataCorrelationMatrix.

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

• Jaccard.cs