Aim: Small class useful to compute the determinant of a 2x2 matrix from its four coefficients, ie. \( \begin{vmatrix} a & x \\ b & y \end{vmatrix} \). More...

#include <DGtal/geometry/tools/determinant/Simple2x2DetComputer.h>

Public Types
typedef TArgumentInteger	ArgumentInteger

typedef ArgumentInteger	Integer

typedef ArgumentInteger	argument_type

typedef TResultInteger	ResultInteger

typedef ResultInteger	Value

typedef ResultInteger	result_type

Public Member Functions
	BOOST_CONCEPT_ASSERT ((concepts::CEuclideanRing< ArgumentInteger >))

	BOOST_CONCEPT_ASSERT ((concepts::CEuclideanRing< ArgumentInteger >))

	Simple2x2DetComputer ()

	Simple2x2DetComputer (const Simple2x2DetComputer &other)

Simple2x2DetComputer &	operator= (const Simple2x2DetComputer &other)

	~Simple2x2DetComputer ()

void	init (const ArgumentInteger &aA, const ArgumentInteger &aB)

ResultInteger	operator() (const ArgumentInteger &aX, const ArgumentInteger &aY) const

ResultInteger	operator() (const ArgumentInteger &aA, const ArgumentInteger &aB, const ArgumentInteger &aX, const ArgumentInteger &aY)

void	selfDisplay (std::ostream &out) const

bool	isValid () const

Private Attributes
ResultInteger	myA

ResultInteger	myB

ResultInteger	myAY

ResultInteger	myBX

Detailed Description

template<typename TArgumentInteger, typename TResultInteger = TArgumentInteger>
class DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >

Aim: Small class useful to compute the determinant of a 2x2 matrix from its four coefficients, ie. \( \begin{vmatrix} a & x \\ b & y \end{vmatrix} \).

This class, which is a model of C2x2DetComputer, just computes the quantity \( ay - bx \).

In order to use Simple2x2DetComputer in its incremental form:

first, you must set the first column vector, ie. \( a \) and \( b \), using method Simple2x2DetComputer::init().
then, you must call method Simple2x2DetComputer::operator() on the second column vector, ie. \( x \) and \( y \).

Note that since a substantial part of the execution time comes from the allocation/desallocation of integers, we follow the same strategy used in IntegerComputer: the user instantiates once this object and computes the determinant several times with it.

Template Parameters

TArgumentInteger	a model of CEuclideanRing for the input coefficients of the 2x2 matrix
TResultInteger	a model of CEuclideanRing for the result. It must be either unbounded or twice as big as TArgumentInteger, ie. if TArgumentInteger is a type coded on b bits, TResultInteger must be coded on 2b+1 bits

Note that if you use the same type for the arguments and the result, the code may fail to provide the exact result because of a possible overflow.

See also: AvnaimEtAl2x2DetSignComputer

Examples: geometry/tools/determinant/exampleInHalfPlane.cpp.

Definition at line 92 of file Simple2x2DetComputer.h.

Member Typedef Documentation

◆ argument_type

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef ArgumentInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::argument_type

STL alias of type ArgumentInteger

Definition at line 108 of file Simple2x2DetComputer.h.

◆ ArgumentInteger

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef TArgumentInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::ArgumentInteger

Type of integer for the input coefficients of the 2x2 matrix

Definition at line 99 of file Simple2x2DetComputer.h.

◆ Integer

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef ArgumentInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::Integer

DGtal alias of type ArgumentInteger

Definition at line 104 of file Simple2x2DetComputer.h.

◆ result_type

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::result_type

STL alias of type ResultInteger

Definition at line 123 of file Simple2x2DetComputer.h.

◆ ResultInteger

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef TResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::ResultInteger

Type of integer for the returned determinant

Definition at line 113 of file Simple2x2DetComputer.h.

◆ Value

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

typedef ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::Value

DGtal alias type of ResultInteger

Definition at line 119 of file Simple2x2DetComputer.h.

Constructor & Destructor Documentation

◆ Simple2x2DetComputer() [1/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::Simple2x2DetComputer ( )

Default constructor.

◆ Simple2x2DetComputer() [2/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::Simple2x2DetComputer ( const Simple2x2DetComputer< TArgumentInteger, TResultInteger > & other )

Copy constructor.

Parameters

other the object to clone.

◆ ~Simple2x2DetComputer()

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::~Simple2x2DetComputer ( )

Destructor.

Member Function Documentation

◆ BOOST_CONCEPT_ASSERT() [1/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::BOOST_CONCEPT_ASSERT ( (concepts::CEuclideanRing< ArgumentInteger >) )

◆ BOOST_CONCEPT_ASSERT() [2/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::BOOST_CONCEPT_ASSERT ( (concepts::CEuclideanRing< ArgumentInteger >) )

◆ init()

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

void DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::init	(	const ArgumentInteger &	aA,
		const ArgumentInteger &	aB
	)

Initialisation.

Parameters

aA	0-component of the first column vector
aB	1-component of the first column vector

See also: operator()

◆ isValid()

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

bool DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::isValid ( ) const

Checks the validity/consistency of the object.

Returns: 'true' if the object is valid, 'false' otherwise.

◆ operator()() [1/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::operator()	(	const ArgumentInteger &	aA,
		const ArgumentInteger &	aB,
		const ArgumentInteger &	aX,
		const ArgumentInteger &	aY
	)

Operator.

Parameters

aA	0-component of the first column vector
aB	1-component of the first column vector
aX	0-component of the second column vector
aY	1-component of the second column vector

Returns: determinant of the 2x2 matrix that consists of the two above column vectors, ie. aA . aY - aB . aX

◆ operator()() [2/2]

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::operator()	(	const ArgumentInteger &	aX,
		const ArgumentInteger &	aY
	)		const

Incremental operator.

Precondition: init must be called before

Parameters

aX	0-component of the second column vector
aY	1-component of the second column vector

Returns: the 2x2 matrix determinant, ie. myAX . aY - myBY . aX

◆ operator=()

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

Simple2x2DetComputer & DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::operator= ( const Simple2x2DetComputer< TArgumentInteger, TResultInteger > & other )

Assignment.

Parameters

other the object to copy.

Returns: a reference on 'this'.

◆ selfDisplay()

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

void DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::selfDisplay ( std::ostream & out ) const

Writes/Displays the object on an output stream.

Parameters

out	the output stream where the object is written.

Field Documentation

◆ myA

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::myA

private

Data member used to store the 0-component of the first column vector, ie. a.

Definition at line 202 of file Simple2x2DetComputer.h.

◆ myAY

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::myAY

mutableprivate

Data member used to store the product ay

Definition at line 211 of file Simple2x2DetComputer.h.

◆ myB

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::myB

private

Data member used to store the 1-component of the first column vector, ie. b.

Definition at line 207 of file Simple2x2DetComputer.h.

◆ myBX

template<typename TArgumentInteger , typename TResultInteger = TArgumentInteger>

ResultInteger DGtal::Simple2x2DetComputer< TArgumentInteger, TResultInteger >::myBX

mutableprivate

Data member used to store the product bx

Definition at line 215 of file Simple2x2DetComputer.h.

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

Simple2x2DetComputer.h

Public Types

Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ argument_type

◆ ArgumentInteger

◆ Integer

◆ result_type

◆ ResultInteger

◆ Value

Constructor & Destructor Documentation

◆ Simple2x2DetComputer() [1/2]

◆ Simple2x2DetComputer() [2/2]

◆ ~Simple2x2DetComputer()

Member Function Documentation

◆ BOOST_CONCEPT_ASSERT() [1/2]

◆ BOOST_CONCEPT_ASSERT() [2/2]

◆ init()

◆ isValid()

◆ operator()() [1/2]

◆ operator()() [2/2]

◆ operator=()

◆ selfDisplay()

Field Documentation

◆ myA

◆ myAY

◆ myB

◆ myBX