lsst::utils::PowFast Class Reference

#include <PowFast.h>

Public Member Functions
float	two (float x) const
	Evaluate 2^x . (x must be in (-125, 128)) More...
float	exp (float x) const
	Evaluate exp(x). (x must be in (-87.3ish, 88.7ish)) More...
float	ten (float x) const
	Evaluate 10^x. (x must be in (-37.9ish, 38.5ish)) More...
float	r (float logr, float x) const
	Evaluate r^x. More...
unsigned int	getPrecision () const
	Return this PowFast's precision. More...

Private Member Functions
	PowFast (unsigned int precision=11)
	~PowFast ()
	PowFast (const PowFast &)
PowFast &	operator= (const PowFast &)

Private Attributes
unsigned int	precision_m
unsigned int *	pTable_m

Friends
template<int >
const PowFast &	getPowFast ()
	return a singleton PowFast with the specified precision in its lookup tables More...

Detailed Description

Definition at line 45 of file PowFast.h.

Constructor & Destructor Documentation

lsst::utils::PowFast::PowFast ( unsigned int  precision = 11 )

explicitprivate

Parameters

precision

Desired precision

Definition at line 125 of file PowFast.cc.

 : precision_m( precision <= 18u ? precision : 18u )
 , pTable_m   ( new unsigned int[ 1 << precision_m ] )
{
   powFastSetTable( pTable_m, precision_m );
}

lsst::utils::PowFast::~PowFast ( )

private

Definition at line 135 of file PowFast.cc.

{
   delete[] pTable_m;
}

lsst::utils::PowFast::PowFast ( const PowFast &  )

private

Member Function Documentation

float lsst::utils::PowFast::exp

(

float

x

)

const

Evaluate exp(x). (x must be in (-87.3ish, 88.7ish))

Parameters

x

exponent

Definition at line 151 of file PowFast.cc.

{
   return powFastLookup( f, 1.44269504088896f, pTable_m, precision_m );
}

unsigned int lsst::utils::PowFast::getPrecision

(

)

const

Return this PowFast's precision.

Definition at line 178 of file PowFast.cc.

{
   return precision_m;
}

PowFast& lsst::utils::PowFast::operator= ( const PowFast &  )

private

float lsst::utils::PowFast::r	(	float	logr,
		float	x
	)		const

Evaluate r^x.

Parameters

logr	log_e(r)
x	desired exponent (beware under/over-flow)

Definition at line 169 of file PowFast.cc.

{
   return powFastLookup( f, (logr * 1.44269504088896f), pTable_m, precision_m );
}

float lsst::utils::PowFast::ten

(

float

x

)

const

Evaluate 10^x. (x must be in (-37.9ish, 38.5ish))

Parameters

x

exponent

Definition at line 160 of file PowFast.cc.

{
   return powFastLookup( f, 3.32192809488736f, pTable_m, precision_m );
}

float lsst::utils::PowFast::two

(

float

x

)

const

Evaluate 2^x . (x must be in (-125, 128))

Parameters

x

exponent

Definition at line 142 of file PowFast.cc.

{
   return powFastLookup( f, 1.0f, pTable_m, precision_m );
}

Friends And Related Function Documentation

template<int >

const PowFast& getPowFast ( )

friend

return a singleton PowFast with the specified precision in its lookup tables

Member Data Documentation

unsigned int lsst::utils::PowFast::precision_m

private

Definition at line 81 of file PowFast.h.

unsigned int* lsst::utils::PowFast::pTable_m

private

Definition at line 82 of file PowFast.h.

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

• /lsst/home/lsstsw/stack/Linux64/utils/master-gf44c96c709/include/lsst/utils/PowFast.h
• /lsst/home/lsstsw/stack/Linux64/utils/master-gf44c96c709/src/PowFast.cc