Butterfly< _Field, Switch > Class Template Reference

Switching Network based BlackBox Matrix. More...

#include <butterfly.h>

Inheritance diagram for Butterfly< _Field, Switch >:

Data Structures
struct	rebind

Public Types
typedef _Field	Field
typedef Butterfly< _Field, Switch >	Self_t
typedef Field::Element	Element

Public Member Functions
	Butterfly (const Field &F, size_t n)
	No-Op Constructor.
	Butterfly (const Field &F, size_t n, typename Switch::Factory &factory)
	Constructor from an integer and a switch object.
	~Butterfly ()
template<class OutVector, class InVector>
OutVector &	apply (OutVector &y, const InVector &x) const
	Application of BlackBox matrix.
template<class OutVector, class InVector>
OutVector &	applyTranspose (OutVector &y, const InVector &x) const
	Application of BlackBox matrix transpose.
template<typename _Tp1, typename _Sw1>
	Butterfly (const Butterfly< _Tp1, _Sw1 > &B, const Field &F)
size_t	rowdim () const
size_t	coldim () const
const Field &	field () const
std::vector< size_t >	n_vec () const
std::vector< size_t >	l_vec () const
std::vector< std::pair< size_t, size_t > >	indices () const
std::vector< size_t > &	n_vec ()
std::vector< size_t > &	l_vec ()
std::vector< std::pair< size_t, size_t > > &	indices ()
std::vector< Switch >::const_iterator	switchesBegin () const
std::vector< Switch >::const_iterator	switchesEnd () const
std::vector< Switch > &	switches ()

Detailed Description

template<class _Field, class Switch = CekstvSwitch<_Field>>
class LinBox::Butterfly< _Field, Switch >

Switching Network based BlackBox Matrix.

A good preconditioner.

Implements butterfly switching network on a LinBox vector as a black box matrix through the use of a switch object.

This is a blackbox matrix object, and it implements all purely virtual methods of the abstract base class. See BlackboxArchetype for the specification of these methods.

This matrix requires a dense vector to be used. Sparse vectors must somehow be converted to dense vectors before this matrix may be applied to them.

Parameters

Vector	LinBox dense vector type
Switch	switch object type

Member Typedef Documentation

Field

template<class _Field, class Switch = CekstvSwitch<_Field>>

typedef _Field Field

Self_t

template<class _Field, class Switch = CekstvSwitch<_Field>>

typedef Butterfly<_Field, Switch> Self_t

Element

template<class _Field, class Switch = CekstvSwitch<_Field>>

typedef Field::Element Element

Constructor & Destructor Documentation

Butterfly() [1/3]

template<class _Field, class Switch = CekstvSwitch<_Field>>

Butterfly ( const Field & F, size_t n )

inline

No-Op Constructor.

Butterfly() [2/3]

template<class Field, class Switch>

Butterfly ( const Field & F, size_t n, typename Switch::Factory & factory )

inline

Constructor from an integer and a switch object.

The switch object is an object that is applied to two references to elements to switch them. It must have both an apply and an applyTranspose method. It must contain all information needed by the switch other than the elements themselves. This includes any random numbers or sequences of values. It must also be able to be applied as many times as needed. In particular, it must be able to create new random elements or repeat a stored sequence of values. This is not required by the abstract base class.

Parameters

n	integer size of vectors to be applied to
F
factory	switch predicate object object

~Butterfly()

template<class _Field, class Switch = CekstvSwitch<_Field>>

~Butterfly ( )

inline

Butterfly() [3/3]

template<class _Field, class Switch = CekstvSwitch<_Field>>

template<typename _Tp1, typename _Sw1>

Butterfly ( const Butterfly< _Tp1, _Sw1 > & B, const Field & F )

inline

Member Function Documentation

apply()

template<class Field, class Switch>

template<class OutVector, class InVector>

OutVector & apply ( OutVector & y, const InVector & x ) const

inline

Application of BlackBox matrix.

y = A*x. Requires one vector conforming to the LinBox vector archetype. Required by abstract base class. For this matrix, this involves applying each switch in order to the input vector.

Returns

reference to vector y containing output (after switching).

Parameters

x	constant reference to vector to contain input (before switching)
y

applyTranspose()

template<class Field, class Switch>

template<class OutVector, class InVector>

OutVector & applyTranspose ( OutVector & y, const InVector & x ) const

inline

Application of BlackBox matrix transpose.

y = transpose (A)*x. Requires one vector conforming to the LinBox vector archetype. Required by abstract base class. For this matrix, this involves applying the transpose of each switch to the input vector in the reverse order of the apply function.

Returns

reference to vector y containing output (after switching).

Parameters

x	constant reference to vector to contain input (before switching)
y

rowdim()

template<class _Field, class Switch = CekstvSwitch<_Field>>

size_t rowdim ( ) const

inline

coldim()

template<class _Field, class Switch = CekstvSwitch<_Field>>

size_t coldim ( ) const

inline

field()

template<class _Field, class Switch = CekstvSwitch<_Field>>

const Field & field ( ) const

inline

n_vec() [1/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< size_t > n_vec ( ) const

inline

l_vec() [1/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< size_t > l_vec ( ) const

inline

indices() [1/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< std::pair< size_t, size_t > > indices ( ) const

inline

n_vec() [2/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< size_t > & n_vec ( )

inline

l_vec() [2/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< size_t > & l_vec ( )

inline

indices() [2/2]

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< std::pair< size_t, size_t > > & indices ( )

inline

switchesBegin()

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< Switch >::const_iterator switchesBegin ( ) const

inline

switchesEnd()

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< Switch >::const_iterator switchesEnd ( ) const

inline

switches()

template<class _Field, class Switch = CekstvSwitch<_Field>>

std::vector< Switch > & switches ( )

inline

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

• butterfly.h
• butterfly.inl