#include <Measure.h>
Inheritance diagram for casa::Measure:
Part of API
Measure forms the abstract base class for physical quantities within a reference frame. Examples of derived classes are:
MeasRef class is templated, but typedefs exist (and should be used) to easily specify the correct one, e.g. MEpoch::Ref.MeasRef frame and an output MeasRef frame it constructs a conversion functional, that can be fed values (with the () operator</tt>).
Some conversions can, in addition to the main type (like TAI), specify details to completely describe any conversion process (e.g. the type of nutation calculation) by specifying Aipsrc keyword/value pairs.
Measures can in general be constructed from a MeasRef and a value. The value can be expressed in the internally used units (e.g. MVEpoch for MEpoch, MVDirection for MDirection), or as a Quantum, i.e. a value with a dimension (e.g. (20,"km/s")) (see Quantum class). The preferred way of construction is by using the constructor: where the reference can be omitted, defaulting to Measure(MVmeasure, Measure::Ref)
Measure::DEFAULT), or in simple cases (not needing additional frame information) be specified directly as a code (e.g. MEpoch::IAT).
The value of the Measure can be obtained by a variety of get functions, returning in general internal or Quantum values. The preferred way is a getValue(void), which returns the specific MVmeasure value, which can then be further formatted using the appropiate MVmeasure get() functions.
Special formatting (like hh:mm:ss.t, dd.mm.ss.t, yy/mm/dd etc) are catered for in conversion-type classes like MVAngle , MVTime .
Conversion (within a Measure type) from one reference frame to another is done by the MeasConvert class. The class is templated, but has typedefs Measure::Convert (e.g. MEpoch::Convert) for easy, and recommended, reference.
The basic constructors for a Measure::Convert are: The // With a default Measure included
Measure::Convert(Measure val, Measure::Ref outref);
// With only input and output reference frames given
Mesaure::Convert( Measure::Ref inref, Measure::Ref outref);
val is used as a model for subsequent input values into this conversion engine, including possible units; the outref specifies the output reference frame wanted. The constructor analyses the conversion wanted, and sets up a vector of routine calls to be called in sequence for the conversion. The actual conversion is done by the () operator</tt>.
To aid in using the raw measures, each class has also a Measure::MVType and Measure::MCType defined. They denote respectively the Measure Value class of the internal value, and the class with conversion routines.
Tip: In the member description a number of dummy routines are present. They are the only way I have found to get cxx2html to get the belonging text properly present.
Example
Which generates the output: \#include <measures/Measures.h>
\#include <casa/Measure/MEpoch.h>
// Example is only to show what can be done, not the easiest way
// Set up a simple reference (no offset or secondary Measures). It
// indicates that times are given in MJD TAI.
MEpoch::Ref reftai(MEpoch::TAI);
// Same, but indicating MJD UTC
MEpoch::Ref refutc(MEpoch::UTC);
// Set up an MEpoch (note that no reference is given. In that case a
// default is assumed (for MEpoch UTC). MJD2000 is a provided constant
// of the MJD at 2000.0
MEpoch UTCval(Quantity(MeasData::MJD2000, "d"), reftai);
// Set up, just for fun, an epoch, UTC for B1950.0:
MEpoch val1950(Quantity(MeasData::MJDB1950, "d"));
// and use it as an offset in a reference
MEpoch::Ref ref1950(MEpoch::TAI, val1950);
// An epoch for J2000 with an offset of B1950.0 will than be
MEpoch val20_50(Quantity(MeasData::MJD2000-MeasData::MJDB1950, "d"),
ref1950);
// Set up conversion from TAI(with values in days w.r.t. B1950.0) to UTC:
MEpoch::Convert tai_to_utc(val20_50, refutc);
// And convert a value (in this case the value in val20_50, the model)
// from TAI(relative to B1950.0) to 'absolute' UTC
MEpoch result = tai_to_utc();
// Show result
cout << "Result 1: " << result << endl;
// To convert 10 years since B1950.0
result = tai_to_utc(Quantity(10.,"a"));
cout << "Result 2: " << result << endl;
// To convert any value in years(the last used units of the model) since B1950.0
result = tai_to_utc(12.3);
cout << "Result 3: " << result << endl;
Result 1: Epoch: 51544::11:59:25.2154
Result 2: Epoch: 36934::10:09:42.1283
Result 3: Epoch: 37774::11:57:41.1085
Motivation
To be able to specify a physical entity absolutely in any reference frame; and to be able to convert from one frame to another. E.g. Local Sidereal Time to Temps Atomic International. A templated version for the MeasRef and MeasConvert was chosen to be able to check most arguments at compile time.
To Do
Definition at line 235 of file Measure.h.
Public Types | |
| enum | Types |
Each derived class should have a Types enumeration, specifying the recognised frame types. More... | |
| typedef void * | Convert |
| Each Measure should have typedefs of the form:. | |
Public Member Functions | |
| virtual | ~Measure () |
| Destructor. | |
| virtual Bool | setOffset (const Measure &in)=0 |
| Set the offset in the reference (False if non-matching Measure). | |
| virtual Bool | areYou (const String &tp) const =0 |
| Check the type of derived Measure entity (e.g. | |
| virtual uInt | type () const=0 |
| Get the type (== Register() of derived Measure (faster than Strings) All should have: static uInt myType();. | |
| virtual const String & | tellMe () const=0 |
| Tell me your Measure type (e.g. | |
| virtual Bool | isModel () const |
| Tell me if you are a pure model (e.g. | |
| virtual Bool | setRefString (const String &in)=0 |
| Set the reference type to the specified String. | |
| virtual const String & | getDefaultType () const=0 |
| Get the default reference type. | |
| virtual const Unit & | getUnit () const=0 |
| Get unit (only available if Measure generated from a Quantum, else ""). | |
| virtual const MeasValue *const | getData () const=0 |
| Get data pointer (used by MeasConvert). | |
| virtual MRBase * | getRefPtr () const=0 |
| Get general reference pointer. | |
| virtual void | print (std::ostream &os) const =0 |
| Print a Measure. | |
| virtual void | set (const MeasValue &dt)=0 |
| Each Measure should have the following set functions (with appropiate MVs and Ref):. | |
| virtual Bool | putValue (const Vector< Quantum< Double > > &in)=0 |
| virtual void | assured (const String &tp) const =0 |
| Assert that we are the correct Measure type. | |
| virtual String | getRefString () const=0 |
| Each Measure should have the following static methods to give its name (e.g. | |
| void | dummy_giveMe () const |
| Dummy for cxx2html. | |
| virtual const String *const | allTypes (Int &nall, Int &nextra, const uInt *&typ) const |
| Get a list of all known reference codes. | |
| virtual void | checkTypes () const=0 |
| Check if all internal tables of types (both enum and String) are complete and correct. | |
| void | dummy_getRef () const |
| Dummy for cxx2html. | |
| void | dummy_getValue () const |
| Each derived class should be able to get its internal value and have:. | |
| virtual Measure * | clone () const=0 |
| Create a copy. | |
Static Public Member Functions | |
| static uInt | giveMe (const String &in, Int N_name, const String tname[]) |
| A general string checking routine to be used in derived measures. | |
Private Member Functions | |
| virtual void | clear ()=0 |
| Clear the measure. | |
| void | dummy_data () const |
| Dummy for cxx2html. | |
Friends | |
| std::ostream & | operator<< (std::ostream &os, const Measure &meas) |
| Each derived class should have:. | |
| typedef void* casa::Measure::Convert |
| enum casa::Measure::Types |
Each derived class should have a Types enumeration, specifying the recognised frame types.
It is formatted as:
Dummy for cxx2html
| virtual casa::Measure::~Measure | ( | ) | [virtual] |
Destructor.
| virtual void casa::Measure::set | ( | const MeasValue & | dt | ) | [pure virtual] |
Set the offset in the reference (False if non-matching Measure).
Check the type of derived Measure entity (e.g.
"Epoch")
| virtual uInt casa::Measure::type | ( | ) | const [pure virtual] |
Get the type (== Register() of derived Measure (faster than Strings) All should have: static uInt myType();.
| virtual void casa::Measure::assured | ( | const String & | tp | ) | const [pure virtual] |
| virtual const String& casa::Measure::tellMe | ( | ) | const [pure virtual] |
Tell me your Measure type (e.g.
"Epoch")
| virtual String casa::Measure::getRefString | ( | ) | const [pure virtual] |
Each Measure should have the following static methods to give its name (e.g.
Epoch) or reference type (e.g. UTC):
// Show the Measure type (e.g. "Direction") static const String &showMe(); // Cast an integer to the appropriate reference type. Avaialable to provide // a safe cast in cases where Measure type is not explicitly known. static Measure::Types castType(uInt tp); // Show the reference type (e.g. MEpoch::showType(MEpoch::IAT) == "TAI") static const String &showType(uInt tp); static const String &showType(Measure::Types tp);
| virtual Bool casa::Measure::isModel | ( | ) | const [virtual] |
Tell me if you are a pure model (e.g.
a planet)
| void casa::Measure::dummy_giveMe | ( | ) | const [inline] |
Set the reference type to the specified String.
False if illegal string, reference set to DEFAULT.
| virtual const String& casa::Measure::getDefaultType | ( | ) | const [pure virtual] |
Get the default reference type.
| virtual void casa::Measure::checkTypes | ( | ) | const [pure virtual] |
A general string checking routine to be used in derived measures.
Its arguments are the string to be converted (in), an array of strings to check against (tname), and its length (N_name). The check is case insensitive and mini-max. A return value less than N_name indicates success.
| void casa::Measure::dummy_getRef | ( | ) | const [inline] |
| void casa::Measure::dummy_getValue | ( | ) | const [inline] |
Each derived class should be able to get its internal value and have:.
const MVmeasure &getValue() const;
Quantity get(const Unit &unit) const; Quantum<Vector<Double> > get(const Unit &unit) const;
| virtual const Unit& casa::Measure::getUnit | ( | ) | const [pure virtual] |
| virtual const MeasValue* const casa::Measure::getData | ( | ) | const [pure virtual] |
Get data pointer (used by MeasConvert).
| virtual MRBase* casa::Measure::getRefPtr | ( | ) | const [pure virtual] |
Get general reference pointer.
| virtual void casa::Measure::print | ( | std::ostream & | os | ) | const [pure virtual] |
Print a Measure.
| virtual Measure* casa::Measure::clone | ( | ) | const [pure virtual] |
Create a copy.
| void casa::Measure::dummy_data | ( | ) | const [inline, private] |
| virtual void casa::Measure::clear | ( | ) | [private, pure virtual] |
Clear the measure.
| std::ostream& operator<< | ( | std::ostream & | os, | |
| const Measure & | meas | |||
| ) | [friend] |
Each derived class should have:.
friend class MeasConvert<a_Measure, its_MV, its_MC>;
1.5.1