Rational< IntType > Class Template Reference

#include <vigra/rational.hxx>

Public Types
typedef If< typename TypeTraits< IntType > ::isBuiltinType, IntType, IntType const & >::type	param_type

typedef IntType	value_type

Public Member Functions
Rational &	assign (param_type n, param_type d, bool doNormalize=true)

param_type	denominator () const

bool	is_inf () const

bool	is_ninf () const

bool	is_pinf () const

param_type	numerator () const

bool	operator! () const

Rational &	operator*= (const Rational &r)

Rational &	operator*= (param_type i)

Rational &	operator++ ()

Rational	operator++ (int)

Rational &	operator+= (const Rational &r)

Rational &	operator+= (param_type i)

Rational &	operator-- ()

Rational	operator-- (int)

Rational &	operator-= (const Rational &r)

Rational &	operator-= (param_type i)

Rational &	operator/= (const Rational &r)

Rational &	operator/= (param_type i)

Rational &	operator= (param_type n)

	Rational ()

template<class U >
	Rational (Rational< U > const &r)

	Rational (param_type n)

	Rational (param_type n, param_type d, bool doNormalize=true)

	Rational (double v, double epsilon=1e-4)

int	sign () const

Detailed Description

template<typename IntType>
class vigra::Rational< IntType >

Template for rational numbers.

This template can make use of arbitrary integer types, including user-defined (e.g. infinite precision) ones. Note, however, that overflow in either the numerator or denominator is not detected during calculations – the standard behavior of the integer type (e.g. wrap around) applies.

The class can represent and handle positive and negative infinity resulting from division by zero. Indeterminate expressions such as 0/0 are signaled by a bad_rational exception which is derived from std::domain_error.

Rational implements the required interface of an AlgebraicField and the required numeric andpromotion traits". All arithmetic and comparison operators, as well as the relevant algebraic functions are supported .

See also:

#include <vigra/rational.hxx>
Namespace: vigra

Member Typedef Documentation

typedef IntType value_type

The type of numerator and denominator

typedef If<typename TypeTraits<IntType>::isBuiltinType, IntType, IntType const &>::type param_type

Determine whether arguments should be passed as IntType or IntType const &.

Constructor & Destructor Documentation

Rational ( )

Default constructor: creates zero (0/1)

Rational ( Rational< U > const & r )

Copy constructor

Rational ( param_type n )

Integer constructor: creates n/1

Rational	(	param_type	n,
		param_type	d,
		bool	doNormalize = `true`
	)

Ratio constructor: creates n/d.

The ratio will be normalized unless doNormalize = false. Since the internal representation is assumed to be normalized, doNormalize = false must only be used as an optimization if n and d are known to be already normalized (i.e. have 1 as their greatest common divisor).

Rational	(	double	v,
		double	epsilon = `1e-4`
	)

explicit

Construct as an approximation of a real number.

The maximal allowed relative error is given by epsilon.

Member Function Documentation

Rational& operator= ( param_type n )

Assignment from IntType.

Rational< IntType > & assign	(	param_type	n,
		param_type	d,
		bool	doNormalize = `true`
	)

Assignment from IntType pair.

param_type numerator ( ) const

Access numerator.

param_type denominator ( ) const

Access denominator.

Rational< IntType > & operator+= ( const Rational< IntType > & r )

Add-assignment from Rational