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casa::UnitMap Class Reference

contains all simple known physical units More...

#include <UnitMap.h>

List of all members.

Public Member Functions

 UnitMap ()
 Default constructor of maps.
 ~UnitMap ()
 Destructor.

Static Public Member Functions

static void releaseUM ()
 Remove all maps (just to get no memory leaks at end of program)
static void putCache (const String &s, const UnitVal &val)
 Save a definition of a full unit name in the cache (the cache will be cleared if getting too large (200 entries)
static void removeUser (const String &name)
 Remove a user unit.
static void removeUser (const UnitName &name)
static void clearCache ()
 Clear out the cache.
static void addFITS ()
 Define FITS related unit names.
static void clearFITS ()
 Clear FITS related units from user list.
static Unit fromFITS (const Unit &un)
 Translate a FITS unit to the proper units.
static Unit toFITS (const Unit &un)
 Translate to a FITS unit.
static Bool getPref (const String &s, UnitName &name)
 Check if a unit name is known, and return its value if True.
static Bool getCache (const String &s, UnitVal &val)
 Get a cached definition.
static Bool getUnit (const String &s, UnitName &name)
 Get a standard unit definition (search order: User, Customary, SI)
static void putUser (const String &s, const UnitVal &val)
 Define a user defined standard unit.
static void putUser (const String &s, const UnitVal &val, const String &name)
static void putUser (const UnitName &name)
static map< String, UnitName > * mapPref
 Decimal prefix list.
static map< String, UnitName > * mapDef
 Defining SI unit list.
static map< String, UnitName > * mapSI
 SI unit list.
static map< String, UnitName > * mapCust
 Customary list.
static map< String, UnitName > * mapUser
 User defined unit list.
static map< String, UnitVal > * mapCache
 Cached list.
static Bool doneFITS
 FITS unit list inclusion.
static void list (ostream &os)
 List some part of the standard unit lists on cout or stream.
static void list ()
static void listCache (ostream &os)
 List all units in cache.
static void listCache ()
static void listPref (ostream &os)
 List all prefixes.
static void listPref ()
static void listDef (ostream &os)
 List all defining units.
static void listDef ()
static void listSI (ostream &os)
 List all SI units.
static void listSI ()
static void listCust (ostream &os)
 List all customary units.
static void listCust ()
static void listUser (ostream &os)
 List all user defined units.
static void listUser ()
static const map< String,
UnitName > & 
givePref ()
 Return the different maps.
static const map< String,
UnitName > & 
giveDef ()
static const map< String,
UnitName > & 
giveSI ()
static const map< String,
UnitName > & 
giveCust ()
static const map< String,
UnitName > & 
giveUser ()
static const map< String,
UnitVal > & 
giveCache ()
 UnitMap (const UnitMap &other)
 
   

UnitMapoperator= (const UnitMap &other)
 Copy assignment (not implemented)
static Bool getNameFITS (UnitName *&name, uInt which)
 Get the name of a FITS unit.
static const StringgetStringFITS (uInt which)
 Get the belonging unit to a FITS unit.
static void initUM ()
 Initialise the static map.
static void initUMPrefix ()
 Bits and pieces of initUM() to get compilation speed improved.
static void initUMSI1 ()
static void initUMSI2 ()
static void initUMCust1 ()
static void initUMCust2 ()
static void initUMCust3 ()

Detailed Description

contains all simple known physical units

Intended use:

Public interface

Review Status

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

Prerequisite

Etymology

Based on Units and the Aips++ container classes called 'Map'

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 UnitMap class contains the known standard basic units, and any other basic unit defined by the user of the Unit related classes. The known units are divided into 5 different groups:

  1. Defining units: m, kg, s, A, K, cd, mol, rad, sr, _
  2. SI units: including a.o. Jy, AU etc)
  3. Customary units: e.g. lb, hp, ly etc
  4. User defined units: defined by user (e.g. Beam, KPH, KM)
  5. Cached units: cached unit strings for speed in operations

The full list of known units can be viewed by running the tUnit test program.
Caution: There is a difference between units without a dimension (non-dimensioned I will call them), and undimensioned units; Non-dimensioned examples are "", "%"; undimensioned examples: "beam", "pixel";

Information about the contents of the unit maps can be obtained by the Bool functions (False if not present):

The standard units can be viewed by the following commands, which output to cout:

Units can be defined in the user list by:
Tip: The cache will be cleared if a user defined unit is overwritten, to make sure no old value will be used;

    UnitMap::putUser("tag", UnitVal(factor,"unit"), "full name (optional)");
       or:
    UnitMap::putUser(UnitName);


Caution: If using an explicit Unit variable (e;g; Unit a("5Bolton/beam")), the check on the legality of the given string, and the conversion to the cached canonical value in the variable 'a', is only done at creation time; This means that if the user changes the value of a unit involved by the putUser() method, the unit using it should be re-created ( a = Unit("5Bolton/beam"););
A special set of 'units' used in FITS datasets can be added by the command

This set can be cleared from the user table by:

Note that Unitmap keeps track of the inclusion of the FITS inclusion, making multiple calls inexpensive. The list of current FITS units can be viewed by running the tUnit program, or looking at the FITSunit table.

Once the UnitMap::addFITS() has been run, the FITS units can be used as any other unit. In addition, a FITS unit can be translated to standard SI units by a call to Unit UnitMap::fromFITS(const Unit). Any unit that is defined as a standard FITS unit will be translated. Unknown ones will not be translated, making the way clear for having standard units in a FITS units string. A comparable toFITS() translates in the same way in the reversed direction.

The cache can be cleared by:

Example

Check for legal prefix:

        UnitName myUnit;
        if (UnitMap::getPref("k", myUnit)) { cout << "k has value " << myUnit;}

Define a value for the unit 'beam':

    UnitMap::putUser("beam",UnitVal(C::pi * 0.1, "\"_2"),"telescope beam");

List current cache:

Motivation

Standard list available to try to enhance use of SI and related units

To Do

Definition at line 188 of file UnitMap.h.


Constructor & Destructor Documentation

Default constructor of maps.

Destructor.

casa::UnitMap::UnitMap ( const UnitMap other) [private]

   

Copy constructor (not implemented)


Member Function Documentation

static void casa::UnitMap::addFITS ( ) [static]

Define FITS related unit names.

static void casa::UnitMap::clearCache ( ) [static]

Clear out the cache.

static void casa::UnitMap::clearFITS ( ) [static]

Clear FITS related units from user list.

static Unit casa::UnitMap::fromFITS ( const Unit un) [static]

Translate a FITS unit to the proper units.

Note that this is a translation of the string only, no conversion. Unknown FITS units are not translated. Hence any new definition of the FITS units will work ok

static Bool casa::UnitMap::getCache ( const String s,
UnitVal val 
) [static]

Get a cached definition.

static Bool casa::UnitMap::getNameFITS ( UnitName *&  name,
uInt  which 
) [static, private]

Get the name of a FITS unit.

static Bool casa::UnitMap::getPref ( const String s,
UnitName name 
) [static]

Check if a unit name is known, and return its value if True.

Get a prefix definition from key

static const String& casa::UnitMap::getStringFITS ( uInt  which) [static, private]

Get the belonging unit to a FITS unit.

static Bool casa::UnitMap::getUnit ( const String s,
UnitName name 
) [static]

Get a standard unit definition (search order: User, Customary, SI)

static const map<String, UnitVal>& casa::UnitMap::giveCache ( ) [static]
static const map<String, UnitName>& casa::UnitMap::giveCust ( ) [static]
static const map<String, UnitName>& casa::UnitMap::giveDef ( ) [static]
static const map<String, UnitName>& casa::UnitMap::givePref ( ) [static]

Return the different maps.

static const map<String, UnitName>& casa::UnitMap::giveSI ( ) [static]
static const map<String, UnitName>& casa::UnitMap::giveUser ( ) [static]
static void casa::UnitMap::initUM ( ) [static, private]

Initialise the static map.

static void casa::UnitMap::initUMCust1 ( ) [static, private]
static void casa::UnitMap::initUMCust2 ( ) [static, private]
static void casa::UnitMap::initUMCust3 ( ) [static, private]
static void casa::UnitMap::initUMPrefix ( ) [static, private]

Bits and pieces of initUM() to get compilation speed improved.

static void casa::UnitMap::initUMSI1 ( ) [static, private]
static void casa::UnitMap::initUMSI2 ( ) [static, private]
static void casa::UnitMap::list ( ostream &  os) [static]

List some part of the standard unit lists on cout or stream.

List all known unit symbols

static void casa::UnitMap::list ( ) [static]
static void casa::UnitMap::listCache ( ostream &  os) [static]

List all units in cache.

static void casa::UnitMap::listCache ( ) [static]
static void casa::UnitMap::listCust ( ostream &  os) [static]

List all customary units.

static void casa::UnitMap::listCust ( ) [static]
static void casa::UnitMap::listDef ( ostream &  os) [static]

List all defining units.

static void casa::UnitMap::listDef ( ) [static]
static void casa::UnitMap::listPref ( ostream &  os) [static]

List all prefixes.

static void casa::UnitMap::listPref ( ) [static]
static void casa::UnitMap::listSI ( ostream &  os) [static]

List all SI units.

static void casa::UnitMap::listSI ( ) [static]
static void casa::UnitMap::listUser ( ostream &  os) [static]

List all user defined units.

static void casa::UnitMap::listUser ( ) [static]
UnitMap& casa::UnitMap::operator= ( const UnitMap other) [private]

Copy assignment (not implemented)

static void casa::UnitMap::putCache ( const String s,
const UnitVal val 
) [static]

Save a definition of a full unit name in the cache (the cache will be cleared if getting too large (200 entries)

static void casa::UnitMap::putUser ( const String s,
const UnitVal val 
) [static]

Define a user defined standard unit.

If the unit is being redefined, and it has already been used in a user's Unit variable, the value cached in that variable will not change.

static void casa::UnitMap::putUser ( const String s,
const UnitVal val,
const String name 
) [static]
static void casa::UnitMap::putUser ( const UnitName name) [static]
static void casa::UnitMap::releaseUM ( ) [static]

Remove all maps (just to get no memory leaks at end of program)

static void casa::UnitMap::removeUser ( const String name) [static]

Remove a user unit.

static void casa::UnitMap::removeUser ( const UnitName name) [static]
static Unit casa::UnitMap::toFITS ( const Unit un) [static]

Translate to a FITS unit.


Member Data Documentation

Bool casa::UnitMap::doneFITS [static, private]

FITS unit list inclusion.

Definition at line 332 of file UnitMap.h.

map<String, UnitVal>* casa::UnitMap::mapCache [static, private]

Cached list.

Definition at line 330 of file UnitMap.h.

map<String, UnitName>* casa::UnitMap::mapCust [static, private]

Customary list.

Definition at line 324 of file UnitMap.h.

map<String, UnitName>* casa::UnitMap::mapDef [static, private]

Defining SI unit list.

Definition at line 318 of file UnitMap.h.

map<String, UnitName>* casa::UnitMap::mapPref [static, private]

Decimal prefix list.

Definition at line 315 of file UnitMap.h.

map<String, UnitName>* casa::UnitMap::mapSI [static, private]

SI unit list.

Definition at line 321 of file UnitMap.h.

map<String, UnitName>* casa::UnitMap::mapUser [static, private]

User defined unit list.

Definition at line 327 of file UnitMap.h.


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