#include <UnitVal.h>

Public Member Functions
	UnitVal ()
	Construct an non-dimensioned value of 1.
	UnitVal (const UnitVal &other)
	Copy constructor.
	UnitVal (Double factor)
	Construct an non-dimensioned value.
	UnitVal (Double factor, const String &s, UMaps *=0)
	Construct a fully dimensioned value.
	UnitVal (Double factor, Int pos)
	Construct a value with a single unit at position specified.
	~UnitVal ()
	Destructor.
UnitVal &	operator= (const UnitVal &other)
	Assignment (copy semantics).
UnitVal &	operator*= (const UnitVal &other)
	Manipulate units .
UnitVal &	operator/= (const UnitVal &other)
	Divide different units.
Bool	operator== (const UnitVal &other) const
	Compare the dimensionality of different units.
Bool	operator!= (const UnitVal &other) const
UnitVal	pow (Int p)
	Raise a unit to an integer power.
UnitVal	root (Int p) const
	Take integer root.
UnitVal	sqrt () const
const UnitDim &	getDim () const
	Get the data parts of the unit value definition .
Double	getFac () const
	Get the factor of the unit (as compared to pure SI units).

Static Public Member Functions
static Bool	check (const String &s)
	Convert a unit string to a proper unit value and cache the result.
static Bool	check (const String &s, UnitVal &loc)
	Convert a unit string to a proper unit value, cache the result and compare the dimension with the specified unit value.

Static Public Attributes
static UnitVal	NODIM
	Some constants to check type of units .
static UnitVal	UNDIM
static UnitVal	LENGTH
static UnitVal	MASS
static UnitVal	TIME
static UnitVal	CURRENT
static UnitVal	TEMPERATURE
static UnitVal	INTENSITY
static UnitVal	MOLAR
static UnitVal	ANGLE
static UnitVal	SOLIDANGLE

Protected Member Functions
void	init (Double factor)
	alternate initialization
void	init (Double factor, Int pos)

Static Private Member Functions
static Bool	create (const String &s, UnitVal &res, UMaps *=0)
	Convert (and check) a unit string to an SI value representation.
static Bool	create (MUString &str, UnitVal &res, UMaps *=0)
static Int	psign (MUString &str)
	Determine sign of unit power (i.e.
static Int	power (MUString &str)
	Determine exponent of unit symbol.
static Bool	field (MUString &str, UnitVal &res, UMaps *)
	Determine symbol name in unit string.

Private Attributes
Double	kindFactor
	The factor necessary to express the specified unit in the defining SI units.
UnitDim	kindDim
	The dimensions of the unit in the defining SI units.

Friends
class	UnitVal_static_initializer
	ensure that statics are initialized
UnitVal	operator* (const UnitVal &in, const UnitVal &other)
	Multiply.
UnitVal	operator/ (const UnitVal &in, const UnitVal &other)
	Divide.
ostream &	operator<< (ostream &os, const UnitVal &ku)
	Output a unit as a value and a string of SI defining units.

Detailed Description

describes any valid unit as a factor and a dimenion of SI units

Intended use:

Public interface

Review Status

Reviewed By:: UNKNOWN
Date Reviewed:: before2004/08/25
Test programs:: tUnit

Prerequisite

Unit

Etymology

The class name derives from Units and gives a Value for a unit string

Synopsis

Physical units are strings consisting of one or more names of known basic units, separated by '.' or ' ' (for multiplication) or '/' (for division). Each name can optionally be preceded by a standard decimal prefix, and/or followed by an (optionally signed) exponent. Example: km/s/(Mpc.s)2 is identical to km.s-1.Mpc-2.s-2

See the Unit class for more details.

The UnitVal class maps a Unit string to a factor and a dimension of SI defining units. E.g 'km/s' will be 1000 m.s-1. This class is only of interest if the manipulation of units is of direct interest. Normally units will be used as Quantities and Quantums (see the Quantum class) only, i.e. as a physical quantity having a value and unit. The class can also be used to check the validity of a unit string.

Constructing UnitVal values

UnitVal has the following constructors:

UnitVal() creates an (non-dimensioned) value 1.
UnitVal(Double f) creates an (non-dimensioned) value f.
UnitVal(Double f, String s) creates value f with unit s
UnitVal(Double f, Int i) (private) creates value f with unit at position i in dimension vector

Manipulating unit values

The UnitVal can be manipulated by the following operators and functions:

*, / generates combined UnitVal (e.g. 1 yd * 1 m = 0.9 m2)
pow(Int) UnitVal(2,"km")->pow(2) = 4000000 m2
root(Int) UnitVal(4000000,"m2")->root(2) = 2 km
==, != compares dimensions only: 1 yd == 5 ly: True
getFac() will return the factor (Double)
getDim() will return the dimensions (as UnitDim)
<< will output formatted unit (factor and dimension)

To aid in checking the dimensionality of units, the following constants are available:

UnitVal::NODIM
UnitVal::UNDIM
UnitVal::LENGTH
UnitVal::MASS
UnitVal::ANGLE
UnitVal::SOLIDANGLE
UnitVal::MOLAR
UnitVal::CURRENT
UnitVal::TIME
UnitVal::TEMPERATURE
UnitVal::INTENSITY

Tip: Any other dimension can be checked by a combination; To check e;g; if a unit is an acceleration, use: UnitVal::LENGTH/UnitVal::TIME/UnitVal::TIME

Checking for valid unit strings

The validity of a unit string can be checked by:

// Check if the given String is a valid unit representation. The String
// will be cached in the unit maps for later reference if True
if (UnitVal::check("km/s/Mpc")) {...}

Example

An observation contains values in Janskys and in Westerbork Units. The data can be combined by the following code:

// The Fits tape gave JY, we check if defined, else we define them
if (!UnitVal::check("JY")) {
UnitMap::putUser("JY", UnitVal(1.,"Jy"), "FITS way to write Jy");
}
// The Fits tape gave WU (which are defined):
// We check if JY and WU are of the same dimension:
if (UnitVal(1.,"JY") != UnitVal(1.,"WU")) {
cerr << "Wrong dimension for either JY (" << 
UnitVal(1.,"JY")->getDim() <<
") or WU (" <<
UnitVal(1.,"WU")->getDim() << ")" << endl;
}
// And output the relation between WU and JY, and the WU value:
cout << "1 WU = " << (UnitVal(1.,"WU")/UnitVal(1.,"Jy"))->getVal() <<
" JY with 1 WU = " << UnitVal(1.,"WU") << endl;

Motivation

To separate the actual manipulation of unit values from the related quantity

To Do

Some inlining (did not work first go)

Definition at line 165 of file UnitVal.h.

Constructor & Destructor Documentation

◆ UnitVal() [1/5]

casacore::UnitVal::UnitVal ( )

Construct an non-dimensioned value of 1.

Referenced by check(), create(), create(), field(), operator!=(), operator*, operator*=(), operator/, operator/=(), operator<<, operator=(), operator==(), pow(), root(), sqrt(), and UnitVal().

◆ UnitVal() [2/5]

casacore::UnitVal::UnitVal ( const UnitVal & other )

Copy constructor.

References UnitVal().

◆ UnitVal() [3/5]

casacore::UnitVal::UnitVal ( Double factor )

inline

Construct an non-dimensioned value.

Definition at line 184 of file UnitVal.h.

References casacore::factor, and casacore::init().

◆ UnitVal() [4/5]

casacore::UnitVal::UnitVal	(	Double	factor,
		const String &	s,
		UMaps *	= 0 )

Construct a fully dimensioned value.

Thrown Exceptions

AipsError

References casacore::factor.

◆ UnitVal() [5/5]

casacore::UnitVal::UnitVal	(	Double	factor,
		Int	pos )

inline

Construct a value with a single unit at position specified.

Definition at line 193 of file UnitVal.h.

References casacore::factor, and casacore::init().

◆ ~UnitVal()

casacore::UnitVal::~UnitVal ( )

Destructor.

Member Function Documentation

◆ check() [1/2]

Bool casacore::UnitVal::check ( const String & s )

static

Convert a unit string to a proper unit value and cache the result.

The function will return False if invalid string specified

◆ check() [2/2]

Bool casacore::UnitVal::check	(	const String &	s,
		UnitVal &	loc )

static

Convert a unit string to a proper unit value, cache the result and compare the dimension with the specified unit value.

False if any of the steps fails

References UnitVal().

◆ create() [1/2]

Bool casacore::UnitVal::create	(	const String &	s,
		UnitVal &	res,
		UMaps *	= 0 )

staticprivate

Convert (and check) a unit string to an SI value representation.

References UnitVal().

◆ create() [2/2]

Bool casacore::UnitVal::create	(	MUString &	str,
		UnitVal &	res,
		UMaps *	= 0 )

staticprivate

References UnitVal().

◆ field()

Bool casacore::UnitVal::field	(	MUString &	str,
		UnitVal &	res,
		UMaps *	)

staticprivate

Determine symbol name in unit string.

References UnitVal().

◆ getDim()

const UnitDim & casacore::UnitVal::getDim ( ) const

Get the data parts of the unit value definition .

Get the dimensions in the defining SI units

◆ getFac()

Double casacore::UnitVal::getFac ( ) const

Get the factor of the unit (as compared to pure SI units).

◆ init() [1/2]

void casacore::UnitVal::init ( Double factor )

protected

alternate initialization

References casacore::factor.

◆ init() [2/2]

void casacore::UnitVal::init	(	Double	factor,
		Int	pos )

protected

References casacore::factor.

◆ operator!=()

Bool casacore::UnitVal::operator!= ( const UnitVal & other ) const

References UnitVal().

◆ operator*=()

UnitVal & casacore::UnitVal::operator*= ( const UnitVal & other )

Manipulate units .

Multiply different units

References UnitVal().

◆ operator/=()

UnitVal & casacore::UnitVal::operator/= ( const UnitVal & other )

Divide different units.

References UnitVal().

◆ operator=()

UnitVal & casacore::UnitVal::operator= ( const UnitVal & other )

Assignment (copy semantics).

References UnitVal().

◆ operator==()

Bool casacore::UnitVal::operator== ( const UnitVal & other ) const

Compare the dimensionality of different units.

References UnitVal().

◆ pow()

UnitVal casacore::UnitVal::pow ( Int p )

Raise a unit to an integer power.

References UnitVal().

◆ power()

Int casacore::UnitVal::power ( MUString & str )

staticprivate

Determine exponent of unit symbol.

◆ psign()

Int casacore::UnitVal::psign ( MUString & str )

staticprivate

Determine sign of unit power (i.e.

if '.' or '/')

◆ root()

UnitVal casacore::UnitVal::root ( Int p ) const

Take integer root.

Thrown Exceptions

AipsError if power equals zero
AipsError if unit dimensions not multiple of power

References UnitVal().

◆ sqrt()

UnitVal casacore::UnitVal::sqrt ( ) const

References UnitVal().

◆ operator*

UnitVal operator*	(	const UnitVal &	in,
		const UnitVal &	other )

friend

Multiply.

References UnitVal().

◆ operator/

UnitVal operator/	(	const UnitVal &	in,
		const UnitVal &	other )

friend

Divide.

References UnitVal().

◆ operator<<

ostream & operator<<	(	ostream &	os,
		const UnitVal &	ku )

friend

Output a unit as a value and a string of SI defining units.

References UnitVal().

◆ UnitVal_static_initializer

friend class UnitVal_static_initializer

friend

ensure that statics are initialized

Definition at line 174 of file UnitVal.h.

References UnitVal_static_initializer.

Referenced by UnitVal_static_initializer.

Member Data Documentation

◆ ANGLE

UnitVal casacore::UnitVal::ANGLE

static

Definition at line 262 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ CURRENT

UnitVal casacore::UnitVal::CURRENT

static

Definition at line 258 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ INTENSITY

UnitVal casacore::UnitVal::INTENSITY

static

Definition at line 260 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ kindDim

UnitDim casacore::UnitVal::kindDim

private

The dimensions of the unit in the defining SI units.

Definition at line 276 of file UnitVal.h.

◆ kindFactor

Double casacore::UnitVal::kindFactor

private

The factor necessary to express the specified unit in the defining SI units.

Definition at line 273 of file UnitVal.h.

◆ LENGTH

UnitVal casacore::UnitVal::LENGTH

static

Definition at line 255 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ MASS

UnitVal casacore::UnitVal::MASS

static

Definition at line 256 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ MOLAR

UnitVal casacore::UnitVal::MOLAR

static

Definition at line 261 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ NODIM

UnitVal casacore::UnitVal::NODIM

static

Some constants to check type of units .

Definition at line 253 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ SOLIDANGLE

UnitVal casacore::UnitVal::SOLIDANGLE

static

Definition at line 263 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ TEMPERATURE

UnitVal casacore::UnitVal::TEMPERATURE

static

Definition at line 259 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ TIME

UnitVal casacore::UnitVal::TIME

static

Definition at line 257 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

◆ UNDIM

UnitVal casacore::UnitVal::UNDIM

static

Definition at line 254 of file UnitVal.h.

Referenced by casacore::UnitVal_static_initializer::UnitVal_static_initializer().

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

casa/Quanta/UnitVal.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Static Private Member Functions

Private Attributes

Friends

Detailed Description

Intended use:

Review Status

Prerequisite

Etymology

Synopsis

Constructing UnitVal values

Manipulating unit values

Checking for valid unit strings

Example

Motivation

To Do

Constructor & Destructor Documentation

◆ UnitVal() [1/5]

◆ UnitVal() [2/5]

◆ UnitVal() [3/5]

◆ UnitVal() [4/5]

Thrown Exceptions

◆ UnitVal() [5/5]

◆ ~UnitVal()

Member Function Documentation

◆ check() [1/2]

◆ check() [2/2]

◆ create() [1/2]

◆ create() [2/2]

◆ field()

◆ getDim()

◆ getFac()

◆ init() [1/2]

◆ init() [2/2]

◆ operator!=()

◆ operator*=()

◆ operator/=()

◆ operator=()

◆ operator==()

◆ pow()

◆ power()

◆ psign()

◆ root()

Thrown Exceptions

◆ sqrt()

Friends And Related Symbol Documentation

◆ operator*

◆ operator/

◆ operator<<

◆ UnitVal_static_initializer

Member Data Documentation

◆ ANGLE

◆ CURRENT

◆ INTENSITY

◆ kindDim

◆ kindFactor

◆ LENGTH

◆ MASS

◆ MOLAR

◆ NODIM

◆ SOLIDANGLE

◆ TEMPERATURE

◆ TIME

◆ UNDIM