DGtal::ModuloComputer< TInteger > Class Template Reference

implements basic functions on modular arithmetic. More...

#include <DGtal/arithmetic/ModuloComputer.h>

Public Types
typedef TInteger	Integer
typedef NumberTraits< Integer >::ParamType	IntegerParamType
typedef NumberTraits< TInteger >::UnsignedVersion	UnsignedInteger
typedef NumberTraits< UnsignedInteger >::ParamType	UnsignedIntegerParamType

Public Member Functions
	BOOST_CONCEPT_ASSERT ((concepts::CInteger< Integer >))
	ModuloComputer (UnsignedIntegerParamType m)
void	increment (UnsignedInteger &i) const
void	decrement (UnsignedInteger &i) const
UnsignedInteger	next (UnsignedIntegerParamType i) const
UnsignedInteger	previous (UnsignedIntegerParamType i) const
UnsignedInteger	cast (IntegerParamType i) const
bool	less (UnsignedIntegerParamType i, UnsignedIntegerParamType j) const
UnsignedInteger	posDiff (UnsignedIntegerParamType j, UnsignedIntegerParamType i) const
void	selfDisplay (std::ostream &out) const
bool	isValid () const

Protected Member Functions
	ModuloComputer ()

Private Member Functions
	ModuloComputer (const ModuloComputer &other)
ModuloComputer &	operator= (const ModuloComputer &other)

Private Attributes
UnsignedInteger	k

Detailed Description

template<typename TInteger>
class DGtal::ModuloComputer< TInteger >

implements basic functions on modular arithmetic.

Description of template class 'ModuloComputer'

Template Parameters

TInteger

type of integer.

Example:

...
//Construct an arithmetic modulo 15
// Note that MyInteger must be a model of the concept CInteger
ModuloComputer<MyInteger> modular(15);
typedef MyInteger::UnsignedVersion myUnsignedInteger;
 
myUnsignedInteger a;
 
a = modular.cast( 2 );   //a contains the value 2
a = modular.cast( -1 );  //a contains the value 14
modular.increment( a ); //a contains the value 0
...

Definition at line 79 of file ModuloComputer.h.

Member Typedef Documentation

Integer

template<typename TInteger >

typedef TInteger DGtal::ModuloComputer< TInteger >::Integer

Definition at line 82 of file ModuloComputer.h.

IntegerParamType

template<typename TInteger >

typedef NumberTraits<Integer>::ParamType DGtal::ModuloComputer< TInteger >::IntegerParamType

Definition at line 83 of file ModuloComputer.h.

UnsignedInteger

template<typename TInteger >

typedef NumberTraits<TInteger>::UnsignedVersion DGtal::ModuloComputer< TInteger >::UnsignedInteger

Definition at line 85 of file ModuloComputer.h.

UnsignedIntegerParamType

template<typename TInteger >

typedef NumberTraits<UnsignedInteger>::ParamType DGtal::ModuloComputer< TInteger >::UnsignedIntegerParamType

Definition at line 86 of file ModuloComputer.h.

Constructor & Destructor Documentation

ModuloComputer() [1/3]

template<typename TInteger >

DGtal::ModuloComputer< TInteger >::ModuloComputer

(

UnsignedIntegerParamType

m

)

Initializes the modulo computer with the value [m].

Parameters

m	any non-zero integer.

ModuloComputer() [2/3]

template<typename TInteger >

DGtal::ModuloComputer< TInteger >::ModuloComputer ( )

protected

Constructor. Forbidden by default (protected to avoid g++ warnings).

ModuloComputer() [3/3]

template<typename TInteger >

DGtal::ModuloComputer< TInteger >::ModuloComputer ( const ModuloComputer< TInteger > &  other )

private

Copy constructor.

Parameters

other

the object to clone. Forbidden by default.

Member Function Documentation

BOOST_CONCEPT_ASSERT()

template<typename TInteger >

DGtal::ModuloComputer< TInteger >::BOOST_CONCEPT_ASSERT

(

(concepts::CInteger< Integer >)

)

cast()

template<typename TInteger >

UnsignedInteger DGtal::ModuloComputer< TInteger >::cast

(

IntegerParamType

i

)

const

Parameters

i	any integer value.

Returns

the value of [i] modulo [k]. NB: O ( i/k ) operation.

Referenced by testModuloComputer().

decrement()

template<typename TInteger >

void DGtal::ModuloComputer< TInteger >::decrement

(

UnsignedInteger &

i

)

const

Decrement the value [i] modulo.

Parameters

i	any value between 0 and [k] (excluded).

increment()

template<typename TInteger >

void DGtal::ModuloComputer< TInteger >::increment

(

UnsignedInteger &

i

)

const

Increment the value [i] modulo.

Parameters

i	any value between 0 and [k] (excluded).

Referenced by testModuloComputer().

isValid()

template<typename TInteger >

bool DGtal::ModuloComputer< TInteger >::isValid

(

)

const

Checks the validity/consistency of the object.

Returns

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

less()

template<typename TInteger >

bool DGtal::ModuloComputer< TInteger >::less	(	UnsignedIntegerParamType	i,
		UnsignedIntegerParamType	j
	)		const

Less comparator modulo. Be careful, modulo comparisons have no sense when the absolute difference of the values are around k / 2.

Parameters

i	any value between 0 and [k] (excluded).
j	any value between 0 and [k] (excluded).

Returns

'true' if [i] strictly precedes [j] in a window 'floor([k]/2)'.

next()

template<typename TInteger >

UnsignedInteger DGtal::ModuloComputer< TInteger >::next

(

UnsignedIntegerParamType

i

)

const

Parameters

i	any value between 0 and [k] (excluded).

Returns

the incremented value of [i] modulo [k].

operator=()

template<typename TInteger >

ModuloComputer & DGtal::ModuloComputer< TInteger >::operator= ( const ModuloComputer< TInteger > &  other )

private

Assignment.

Parameters

other

the object to copy.

Returns

a reference on 'this'. Forbidden by default.

posDiff()

template<typename TInteger >

UnsignedInteger DGtal::ModuloComputer< TInteger >::posDiff	(	UnsignedIntegerParamType	j,
		UnsignedIntegerParamType	i
	)		const

Performs j - i modulo, assuming less(i,j) is true.

Parameters

j	any value between 0 and [k] (excluded).
i	any value between 0 and [k] (excluded).

Returns

the value j - i, always positive.

previous()

template<typename TInteger >

UnsignedInteger DGtal::ModuloComputer< TInteger >::previous

(

UnsignedIntegerParamType

i

)

const

Parameters

i	any value between 0 and [k] (excluded).

Returns

the decremented value of [i] modulo [k].

selfDisplay()

template<typename TInteger >

void DGtal::ModuloComputer< TInteger >::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

k

template<typename TInteger >

UnsignedInteger DGtal::ModuloComputer< TInteger >::k

private

Modulo of all computations.

Definition at line 164 of file ModuloComputer.h.

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

• ModuloComputer.h