#include <tbox/MathUtilities.h>

Public Member Functions
bool	isNaN (const float &value)

bool	isNaN (const double &value)

bool	isNaN (const dcomplex &value)

bool	equalEps (const float &a, const float &b)

bool	equalEps (const double &a, const double &b)

bool	equalEps (const dcomplex &a, const dcomplex &b)

bool	Rand (const bool &low, const bool &width)

char	Rand (const char &low, const char &width)

int	Rand (const int &low, const int &width)

float	Rand (const float &low, const float &width)

double	Rand (const double &low, const double &width)

dcomplex	Rand (const dcomplex &low, const dcomplex &width)

dcomplex	Min (dcomplex a, dcomplex b)

dcomplex	Max (dcomplex a, dcomplex b)

int	Abs (int a)

float	Abs (float a)

double	Abs (double a)

float	round (float a)

double	round (double a)

Static Public Member Functions
static TYPE	getZero ()
	Return the value 0 for the template type. More...

static TYPE	getOne ()
	Return the value 1 for the template type. More...

static TYPE	getSignalingNaN ()
	Return the IEEE signaling NaN for the template type on architectures that support it. More...

static bool	isNaN (const TYPE &value)
	Return true if the supplied value is NaN; else, false. More...

static void	setArrayToSignalingNaN (Array< TYPE > &array)
	Set array entries to value given by getSignalingNaN(). More...

static void	setArrayToSignalingNaN (TYPE *array, int n=1)
	Set array entries to value given by getSignalingNaN(). More...

static bool	equalEps (const TYPE &a, const TYPE &b)
	Return true if given values have a relative difference smaller than sqrt(mach_eps) for the template type. More...

static TYPE	getMax ()
	Return max value for the template type. More...

static void	setArrayToMax (Array< TYPE > &array)
	Set array entries to value given by getMax(). More...

static void	setArrayToMax (TYPE *array, int n=1)
	Set array entries to value given by getMax(). More...

static TYPE	getMin ()
	Return min value for the template type. More...

static void	setArrayToMin (Array< TYPE > &array)
	Set array entries to value given by getMin(). More...

static void	setArrayToMin (TYPE *array, int n=1)
	Set array entries to value given by getMin(). More...

static TYPE	getEpsilon ()
	Return epsilon value for the template type. More...

static void	setArrayToEpsilon (Array< TYPE > &array)
	Set array entries to value given by getEpsilon(). More...

static void	setArrayToEpsilon (TYPE *array, int n=1)
	Set array entries to value given by getEpsilon(). More...

static TYPE	Min (TYPE a, TYPE b)
	Return the minimum value of a and b. More...

static TYPE	Max (TYPE a, TYPE b)
	Return the maximum value of a and b. More...

static TYPE	Abs (TYPE a)
	Return absolute value of a. More...

static TYPE	round (TYPE a)
	Return nearest integral value. More...

static TYPE	Rand (const TYPE &low, const TYPE &width)
	Generate and return a random value from low to low+width. More...

Private Member Functions
bool	s_zero

bool	s_one

bool	s_signaling_nan

bool	s_max

bool	s_min

bool	s_epsilon

char	s_zero

char	s_one

char	s_signaling_nan

char	s_max

char	s_min

char	s_epsilon

int	s_zero

int	s_one

int	s_signaling_nan

int	s_max

int	s_min

int	s_epsilon

float	s_zero

float	s_one

float	s_signaling_nan

float	s_max

float	s_min

float	s_epsilon

double	s_zero

double	s_one

double	s_signaling_nan

double	s_max

double	s_min

double	s_epsilon

dcomplex	s_zero

dcomplex	s_one

dcomplex	s_signaling_nan

dcomplex	s_max

dcomplex	s_min

dcomplex	s_epsilon

Static Private Attributes
static TYPE	s_zero

static TYPE	s_one

static TYPE	s_signaling_nan

static TYPE	s_max

static TYPE	s_min

static TYPE	s_epsilon

Detailed Description

template<class TYPE>
class SAMRAI::tbox::MathUtilities< TYPE >

Class MathUtilities is a utility that provides some basic math-related functions and routines for initializing data to signaling NaNs and POSIX constants like INT_MAX, FLT_MAX, DBL_MAX, etc. Signaling NaNs force a trap if they are used in a numerical operation, so they are a useful way to track uninitialized floating point data. For example, setting integer values to INT_MAX is a useful way to track uninitialized integer values.

IMPORTANT: To properly trap operations based on signaling NaN values, the routine IEEE::setupFloatingPointExceptionHandlers() must be called. This is normally done in the SAMRAIManager::startup() routine.

The implementation of this class depends heavily on the particular computer architecture and how it implements floating point arithmetic and hardware traps.

Note that the class

See also: tbox::IEEE also provides operations for dealing with signaling NaNs. This class provides the actual implementation for such operations with functions in tbox::IEEE calling the approriate operations provided here. The class tbox::IEEE is not templated on the data type and so calling the operations provided there may be easier in some cases, such as in codes built based on earlier versions of SAMRAI.

Member Function Documentation

◆ getZero()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getZero ( )

static

◆ getOne()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getOne ( )

static

◆ getSignalingNaN()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getSignalingNaN ( )

static

Using this value in a numerical expression will cause a program abort.

For float, double, and dcomplex types, the usual signaling Nan value will be returned if defined for the architecture and compiler. For char and int types, the POSIX max value for the type is returned. For other template types, zero is returned.

◆ isNaN() [1/4]

template<class TYPE >

static bool SAMRAI::tbox::MathUtilities< TYPE >::isNaN ( const TYPE & value )

static

For float and double, will check value against signaling NaN. For dcomplex will return true if either real and imaginary part is signaling NaN and false otherwise.
For other types will return false always.

Parameters

value Value to test

◆ setArrayToSignalingNaN() [1/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToSignalingNaN ( Array< TYPE > & array )

static

Parameters

array SAMRAI array to set

◆ setArrayToSignalingNaN() [2/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToSignalingNaN	(	TYPE *	array,
		int	n = `1`
	)

static

Parameters

array	Pointer to first array entry
n	Integer to number of array entries.

◆ equalEps() [1/4]

template<class TYPE >

static bool SAMRAI::tbox::MathUtilities< TYPE >::equalEps	(	const TYPE &	a,
		const TYPE &	b
	)

static

Valid for float/double/dcomplex only. For dcomplex will return true if both real and imaginary part values have a relative difference smaller than sqrt(mach_eps).

For non float/double/dcomplex will just return ( a == b ).

Parameters

a
b

◆ getMax()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getMax ( )

static

For boolean type, will return "true". For dcomplex type, will return a dcomplex value with both real and imaginary parts set to the POSIX max value for type double. For other types, will return the POSIX max value for the type.

◆ setArrayToMax() [1/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToMax ( Array< TYPE > & array )

static

Parameters

array SAMRAI array to set

◆ setArrayToMax() [2/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToMax	(	TYPE *	array,
		int	n = `1`
	)

static

Parameters

array	Pointer to first array entry
n	Integer to number of array entries.

◆ getMin()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getMin ( )

static

For boolean type, will return "false". For dcomplex type, will return a dcomplex value with both real and imaginary parts set to the POSIX min value for type double. For other types, will return the POSIX min value for the type.

◆ setArrayToMin() [1/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToMin ( Array< TYPE > & array )

static

Parameters

array SAMRAI array to set

◆ setArrayToMin() [2/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToMin	(	TYPE *	array,
		int	n = `1`
	)

static

Parameters

array	Pointer to first array entry
n	Integer to number of array entries.

◆ getEpsilon()

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::getEpsilon ( )

static

For boolean type, will return "true". For integer type, will return "1". For dcomplex type, will return a dcomplex value with both real and imaginary parts set to the POSIX epsilon value for type double. For other types, will return the POSIX epsilon value for the type.

◆ setArrayToEpsilon() [1/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToEpsilon ( Array< TYPE > & array )

static

Parameters

array SAMRAI array to set

◆ setArrayToEpsilon() [2/2]

template<class TYPE >

static void SAMRAI::tbox::MathUtilities< TYPE >::setArrayToEpsilon	(	TYPE *	array,
		int	n = `1`
	)

static

Parameters

array	Pointer to first array entry
n	Integer to number of array entries.

◆ Min() [1/2]

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::Min	(	TYPE	a,
		TYPE	b
	)

static

For dcomplex type will return the value with the minimum norm.

Parameters

a
b

◆ Max() [1/2]

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::Max	(	TYPE	a,
		TYPE	b
	)

static

For dcomplex type will return the value with the maximum norm.

Parameters

a
b

◆ Abs() [1/4]

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::Abs ( TYPE a )

static

For int, float, and double types will return the absolute numerical value. For other types, will return the input value.

Parameters

a

◆ round() [1/3]

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::round ( TYPE a )

static

If the argument is halfway between two integral values then round away from zero for float and double types. For other types, will return the input value.

Parameters

a

◆ Rand() [1/7]

template<class TYPE >

static TYPE SAMRAI::tbox::MathUtilities< TYPE >::Rand	(	const TYPE &	low,
		const TYPE &	width
	)

static

For boolean type, value is either "true" or "false" based on value generated by mrand48(). For other types, returned value is computed as width * drand48() + low. When type is char, this value is cast to a char. When type is dcomplex, real and imaginary parts are computed separately this way.

Parameters