GaussianConvert.h

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// # GaussianConvert.h: Class to convert units of Gaussians from pixel to world
// # Copyright (C) 1997,1998,1999,2000
// # 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 COORDINATES_GAUSSIANCONVERT_H
#define COORDINATES_GAUSSIANCONVERT_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/Vector.h>
#include <casacore/coordinates/Coordinates/CoordinateSystem.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
template <class T>
class Quantum;
 
// <summary>
// Converts Gaussian parameters between pixel and world
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="" tests="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class=CoordinateSystem>CoordinateSystem</linkto>
// </prerequisite>
 
// <synopsis>
// Converts Gaussian parameters between world and pixel.
// In the pixel coordinate system ([0,0] in center of image)
// the position angle is positive +y to -x. This is consistent
// with Gaussian2D.  In the world coordinate system the pa
// is positive N through E
// </synopsis>
 
// <example>
// <srcblock>
// </srcblock>
// </example>
 
// <todo asof="1998/12/11">
//  <li> Position angle signs require more thinking in Casacore
// </todo>
 
class GaussianConvert {
 public:
  // Default constructor
  GaussianConvert();
 
  // Constructor.  You specify which world axes (must be length 2)
  // of the coordinate system are the relevant ones for
  // your gaussian (x then y)
  GaussianConvert(const CoordinateSystem& cSys, const Vector<uInt>& worldAxes);
 
  // Destructor
  ~GaussianConvert();
 
  // Copy constructor.  Uses copy semantics.
  GaussianConvert(const GaussianConvert& other);
 
  // Assignment operator. Uses copy semantics.
  GaussianConvert& operator=(const GaussianConvert& other);
 
  // (Re)set the coordinate system
  void setCoordinateSystem(const CoordinateSystem& cSys);
 
  // Re(set) the world axes
  void setWorldAxes(const Vector<uInt>& worldAxes);
 
  // Convert Gaussian parameters from pixels to world.  Returns
  // False if it fails with an error message recoverable with
  // function errorMessage.  If you set the units of the output
  // axis quanta they will be honoured, otherwise they will come out
  // in the axis units of the coordinate system.  For the output position angle,
  // if the output units are not set, the units of the input position angle
  // will be used.
  Bool toWorld(Quantum<Double>& majorAxisOut, Quantum<Double>& minorAxisOut,
               Quantum<Double>& positionAngleOut, Double majorAxisIn, Double minorAxisIn,
               const Quantum<Double>& positionAngleIn);
 
  // Convert Gaussian parameters from world to pixel.  Returns
  // False if it fails with an error message recoverable with
  // function errorMessage. For the output position angle,
  // if the output units are not set, the units of the input position angle
  // will be used.
  Bool toPixel(Double& majorAxisOut, Double& minorAxisOut, Quantum<Double>& positionAngleOut,
               const Quantum<Double>& majorAxisIn, const Quantum<Double>& minorAxisIn,
               const Quantum<Double>& positionAngleIn);
 
  // Convert location
  // <group>
  Bool toPixel(Vector<Double>& pixel, const Vector<Quantum<Double>>& world);
  Bool toWorld(Vector<Quantum<Double>>& world, const Vector<Double>& pixel);
  // </group>
 
  // Recover error messages from the conversion functions
  String errorMessage() const { return itsErrorMessage; }
 
 private:
  CoordinateSystem itsCSys;
  Vector<uInt> itsWorldAxes;
  String itsErrorMessage;
  Bool itsValid;
 
  void convertAxes(Double& minorAxisOut, Double& majorAxisOut, Quantum<Double>& positionAngleOut,
                   Double minorAxisIn, Double majorAxisIn, const Quantum<Double>& positionAngleIn,
                   const CoordinateSystem& cSys, String dir);
 
  void checkCoordinateSystem();
 
  void checkWorldAxes();
 
  Double positionAngleRange(Double pa);
};
 
}  // namespace casacore
 
#endif