MDoppler.h

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// # MDoppler.h: A Measure: Doppler shift
// # Copyright (C) 1995,1996,1997,1998,1999,2000,2002,2003
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef MEASURES_MDOPPLER_H
#define MEASURES_MDOPPLER_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
#include <casacore/measures/Measures/MeasBase.h>
#include <casacore/measures/Measures/MeasRef.h>
#include <casacore/casa/Quanta/MVDoppler.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class MDoppler;
class MCDoppler;
template <class M>
class MeasConvert;
template <class M>
class ArrayMeasColumn;
template <class M>
class ScalarMeasColumn;
template <class T>
class Quantum;
 
// # Typedefs
 
// <summary>
// A Measure: Doppler shift
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="tMeasure" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class=Measure>Measure</linkto> class
// </prerequisite>
//
// <etymology>
// From Measure and Doppler
// </etymology>
//
// <synopsis>
// MDoppler forms the derived Measure class for Doppler shifts.<br>
// An MDoppler can be generated from a simple value (or an
// <linkto class=MVDoppler>MVDoppler</linkto>), which is then
// interpreted as a Doppler ratio, and a reference, with a RADIO type
// as default.<br>
// It can also be generated from a Quantity, where the interpretation
// depends on the dimensionality of the Quantity:
// <ul>
// <li> None: a Doppler ratio
// <li> Velocity: Doppler ratio calculated by dividing with c
// </ul>
// The different types of Doppler (with F = f/f0, the frequency ratio),
// are:
// <ul>
// <li> MDoppler::Z     (-1 + 1/F)
// <li> MDoppler::RATIO     (F)             *
// <li> MDoppler::RADIO     (1  - F)
// <li> MDoppler::OPTICAL == Z
// <li> MDoppler::BETA      ((1 - F<sup>2</sup>)/(1 + F<sup>2</sup>))
// <li> MDoppler::GAMMA     ((1 + F<sup>2</sup>)/2F)    *
// <li> MDoppler::RELATIVISTIC == BETA (== v/c)
// <li> MDoppler::DEFAULT == RADIO
// </ul>
// Note that the ones with an '*' have no real interpretation (although the
// calculation will proceed) if given as
// a velocity.<br>
// <p>
// Conversion between the different types is done with the standard
// <linkto class=MeasConvert>MeasConvert</linkto> class
// (<src>MDoppler::Convert</src> in this case).<br>
//
// Dopplers can be created from an <linkto class=MFrequency>MFrequency</linkto>
// object, or from an <linkto class=MRadialVelocity>MRadialVelocity</linkto>
// object.<br>
//
// A <em>shiftFrequency()</em> method can shift frequencies.
//
// Dopplers do not need a reference frame.
//
// </synopsis>
//
// <example>
// Conversion of a radio Doppler to an optical
// <srcblock>
//  MDoppler radio(0.01);       // A radio Doppler value
//  cout << "Doppler radio = " << radio << "; optical = " <<
//      MDoppler::Convert(radio, MDoppler::OPTICAL)() << // Convert
//      endl;
// </srcblock>
// Setting up a conversion
// <srcblock>
//  MDoppler::Convert to_opt(MDoppler::RADIO, MDoppler::OPTICAL);
//  for (Double d=0; d<0.1; d += 0.005) {
//      cout << "radio = " << d << " to optical = " <<
//          to_opt(d) << endl;
// </srcblock>
// </example>
//
// <motivation>
// </motivation>
//
// <todo asof="2000/06/15">
//  <li>
// </todo>
 
class MDoppler : public MeasBase<MVDoppler, MeasRef<MDoppler>> {
 public:
  // # Friends
  //  Conversion of data
  friend class MeasConvert<MDoppler>;
 
  // # Enumerations
  //  Types of known MDopplers
  //  <note role=warning> The order defines the order in the translation
  //  matrix FromTo
  //  in the getConvert routine. Do not change the order without
  //  changing the array. Additions should be made before N_types, and
  //  an additional row and column should be coded in FromTo, and
  //  in showType().</note>
  enum Types {
    RADIO,
    Z,
    RATIO,
    BETA,
    GAMMA,
    N_Types,
    OPTICAL = Z,
    RELATIVISTIC = BETA,
    DEFAULT = RADIO
  };
 
  // # Typedefs
  //  Measure value container for this class (i.e. MDoppler::MVType)
  typedef MVDoppler MVType;
  // Measure conversion routines for this class (i.e. MDoppler::MCType)
  typedef MCDoppler MCType;
  // Measure reference (i.e. MDoppler::Ref)
  typedef MeasRef<MDoppler> Ref;
  // Measure Convert (i.e. MDoppler::Convert)
  typedef MeasConvert<MDoppler> Convert;
  // Measure table Columns (e.g., MDoppler::ScalarColumn)
  typedef ScalarMeasColumn<MDoppler> ScalarColumn;
  typedef ArrayMeasColumn<MDoppler> ArrayColumn;
 
  // # Constructors
  //  <note role=tip> In the following constructors and other functions, all
  //  <em>MeasRef</em> can be replaced with simple <src>Measure::TYPE</src>
  //  where no offsets or frames are needed in the reference. </note>
  //  Default constructor; generates a zero rest Doppler
  MDoppler();
  // Create from data and reference
  // <group>
  MDoppler(const MVDoppler &dt);
  MDoppler(const MVDoppler &dt, const MDoppler::Ref &rf);
  MDoppler(const MVDoppler &dt, MDoppler::Types rf);
  MDoppler(const Quantity &dt);
  MDoppler(const Quantity &dt, const MDoppler::Ref &rf);
  MDoppler(const Quantity &dt, MDoppler::Types rf);
  MDoppler(const Measure *dt);
  MDoppler(const MeasValue *dt);
  // </group>
 
  // # Destructor
  virtual ~MDoppler();
 
  // # Operators
 
  // # General Member Functions
  //  Tell me your type
  //  <group>
  virtual const String &tellMe() const;
  static const String &showMe();
  static void assure(const Measure &in);
  // </group>
  // Translate reference code. The uInt version has a check for valid codes
  // (i.e. it is a safe cast).
  // <thrown>
  //   <li> AipsError in the uInt interface if illegal code given
  // </thrown>
  // <group>
  static MDoppler::Types castType(uInt tp);
  static const String &showType(MDoppler::Types tp);
  static const String &showType(uInt tp);
  // </group>
  // Translate string to reference code
  // <group>
  static Bool getType(MDoppler::Types &tp, const String &in);
  Bool giveMe(MDoppler::Ref &mr, const String &in);
  // </group>
  // Set the offset in the reference (False if non-matching Measure)
  virtual Bool setOffset(const Measure &in);
  // Set the reference type to the specified String. False if illegal
  // string, reference set to DEFAULT.
  virtual Bool setRefString(const String &in);
  // Get the default reference type
  virtual const String &getDefaultType() const;
  // Get a list of all known reference codes. nall returns the number in list,
  // nextra the number of specials (like planets) that should be at
  // end of list). typ returns the list of corresponding types.
  // <group>
  virtual const String *allTypes(Int &nall, Int &nextra, const uInt *&typ) const;
  static const String *allMyTypes(Int &nall, Int &nextra, const uInt *&typ);
  // </group>
  // Check if all internal tables of types (both enum and String) are
  // complete and correct. This function is called automatically if and when
  // necessary.
  // <thrown>
  //   <li> AipsError if a (programming) error in the types.
  // </thrown>
  // <group>
  virtual void checkTypes() const;
  static void checkMyTypes();
  // </group>
  // Get the reference type (for records, including codes like R_)
  virtual String getRefString() const;
 
  // Get in specified units
  Quantity get(const Unit &un) const;
 
  // Shift the input frequencies to the output frequencies. In the case of
  // simple Double inputs, it is assumed that the values are linearly dependent
  // on frequency. I.e. frequencies given as wavelength or time cannot be used.
  // <group>
  Vector<Double> shiftFrequency(const Vector<Double> &freq) const;
  Quantum<Vector<Double>> shiftFrequency(const Quantum<Vector<Double>> &freq) const;
  // </group>
 
  // Make a copy
  // <group>
  virtual Measure *clone() const;
  // </group>
 
 private:
  // # Enumerations
 
  // # Data
 
  // # Member functions
};
 
}  // namespace casacore
 
#endif