ExtendSpecifier.h

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// # ExtendSpecifier.h: Specification of new and stretched lattice axes
// # Copyright (C) 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 CASA_EXTENDSPECIFIER_2_H
#define CASA_EXTENDSPECIFIER_2_H
 
// # Includes
#include "IPosition.h"
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class Slicer;
 
// <summary>
// Specification of new and stretched lattice axes
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="yyyy/mm/dd" tests="tExtendSpecifier.cc" demos="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class="IPosition">IPosition</linkto>
// </prerequisite>
 
// <synopsis>
// ExtendSpecifier is a class internally used by casacore class
// ExtendLattice.
// It holds the information which axes are stretched and which axes
// are new. Note that a stretched axis has to have length 1 in the
// original shape.
// <p>
// The class only contains the functionality needed by ExtendLattice.
// which are (mainly) 2 conversion functions. One function converts
// a slicer from the extended lattice to the original lattice, so
// ExtendLattice can read the correct data.
// The other function converts a shape in the original lattice to the
// shape in the extended lattice.
// <br>Some data is precalculated for more efficient processing
// of the conversion of slicers and shapes.
// </synopsis>
 
// <example>
// <srcblock>
// IPosition oldShape(4,10,1,3,1);
// IPosition newShape(5,10,1,5,3,8);
// ExtendSpecifier spec (oldShape, newShape, IPosition(1,2), IPosition(1,4));
// </srcblock>
// This example extends the old shape to the new shape.
// <br>The 3rd argument tells that axes 2 is new. The newShape tells that
// its length will be 5. Note that adding this axis means that axes 2
// in the old shape will get axes 3 in the new shape.
// <br>The 4th argument tells that axes 4 (in the new shape!!) is stretched
// (to 8 according to newShape).
// </example>
 
// # <todo asof="yyyy/mm/dd">
// # </todo>
 
class ExtendSpecifier {
 public:
  // Default constructor generates empty IPositions.
  ExtendSpecifier();
 
  // Tell if no or all degenerate axes have to be removed.
  ExtendSpecifier(const IPosition& oldShape, const IPosition& newShape, const IPosition& newAxes,
                  const IPosition& stretchAxes);
 
  // Return the new shape.
  const IPosition& newShape() const { return itsNewShape; }
 
  // Return the new axes.
  const IPosition& newAxes() const { return itsNewAxes; }
 
  // Return the axes to be stretched.
  const IPosition& stretchAxes() const { return itsStretchAxes; }
 
  // Return the old shape.
  const IPosition& oldShape() const { return itsOldShape; }
 
  // Return the axes to be extended (i.e. new and stretch axes).
  const IPosition& extendAxes() const { return itsExtendAxes; }
 
  // Return the old axes (i.e. axes new nor stretched) as in old shape.
  const IPosition& oldOldAxes() const { return itsOldOldAxes; }
 
  // Return the old axes as in new shape.
  const IPosition& oldNewAxes() const { return itsOldNewAxes; }
 
  // Convert the slicer to the specification for the old shape.
  // It fills <src>shape</src> with the shape to reform the section
  // length such that it contains the new axes.
  Slicer convert(IPosition& shape, const Slicer& section) const;
 
  // Convert a shape to the specification for the new shape.
  IPosition convertNew(const IPosition& oldShape) const;
 
 private:
  // Fill the flags for the given axes.
  // It throws an exception if the axis is invalid or multiply given.
  void fill(bool* flags, size_t nrdim, const IPosition& axes) const;
 
  IPosition itsOldShape;
  IPosition itsNewShape;
  IPosition itsNewAxes;
  IPosition itsStretchAxes;
  IPosition itsExtendAxes;
  IPosition itsOldOldAxes;
  IPosition itsOldNewAxes;
};
 
}  // namespace casacore
 
#endif