LELLattCoordBase.h

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// # LELLattCoordBase.h: The base letter class for lattice coordinates in LEL
// # Copyright (C) 1998,1999,2000,2001
// # 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 LATTICES_LELLATTCOORDBASE_H
#define LATTICES_LELLATTCOORDBASE_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
#include <casacore/casa/BasicSL/String.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class LELImageCoord;
class IPosition;
 
// <summary>
// The base letter class for lattice coordinates in LEL.
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="Bob Garwood" date="2000/01/25" tests="tLatticeExpr">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="Lattice"> Lattice</linkto>
//   <li> <linkto class="LELCoordinates"> LELCoordinates</linkto>
// </prerequisite>
 
// <synopsis>
// This abstract base class is the basic letter for the envelope class
// <linkto class=LELCoordinates>LELCoordinates</linkto>.
// It does not do anything, but makes it possible that derived classes
// (like <linkto class=LELLattCoord>LELLattCoord</linkto> and
// <linkto class=LELImageCoord>LELImageCoord</linkto>)
// implement their own behaviour.
// </synopsis>
 
// <motivation>
// It must be possible to handle image coordinates in a lattice
// expression.
// </motivation>
 
// # <todo asof="1998/01/31">
// #  <li>
// # </todo>
 
class LELLattCoordBase {
 public:
  LELLattCoordBase() {};
 
  // A virtual destructor is needed so that it will use the actual
  // destructor in the derived class.
  virtual ~LELLattCoordBase();
 
  // Does the class have true coordinates?
  virtual Bool hasCoordinates() const = 0;
 
  // The name of the class.
  virtual String classname() const = 0;
 
  // Get the coordinates of the spectral axis for the given shape.
  // It returns the pixel axis number of the spectral coordinates.
  // -1 indicates that there is no pixel spectral axis.
  // An exception is thrown if there are no world spectral coordinates.
  virtual uInt getSpectralInfo(Vector<Double>& worldCoordinates, const IPosition& shape) const = 0;
 
  // Check how the coordinates of this and that compare.
  virtual Int compare(const LELLattCoordBase& other) const = 0;
 
  // Check how the coordinates of this and that image compare.
  // This function is used by <src>conform</src> to make a
  // double virtual dispatch possible.
  virtual Int doCompare(const LELImageCoord& other) const = 0;
};
 
}  // namespace casacore
 
#endif