WCLELMask.h

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// # WCLELMask.h: Class to define a mask as a LEL expression
// # Copyright (C) 2000,2003
// # 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 IMAGES_WCLELMASK_H
#define IMAGES_WCLELMASK_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/images/Regions/WCRegion.h>
#include <casacore/lattices/LRegions/RegionType.h>
#include <casacore/coordinates/Coordinates/CoordinateSystem.h>
#include <casacore/casa/Arrays/Vector.h>
#include <casacore/casa/Quanta/Quantum.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations
class LCRegion;
class TableRecord;
class IPosition;
template <class T>
class ImageExpr;
template <class T>
class LatticeExpr;
class LatticeExprNode;
 
// <summary>
// Class to define a mask as a LEL expression
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="" tests="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class=WCRegion>WCRegion</linkto>
//   <li> <linkto class=ImageExpr>ImageExpr</linkto>
// </prerequisite>
 
// <synopsis>
// The WCLELMask class is a specialization of class
// <linkto class=WCRegion>WCRegion</linkto>.
// <br>
// It can be used to define an on-the-fly mask for an image
// using a boolean <linkto class=LatticeExpr>LatticeExpr</linkto>.
// The contents of the mask are calculated on the fly from the expression.
// Thus the mask may change if the data in the image(s) used in the
// expression change.
// <note role=caution>
// This mask is only persistent if constructed from an expression string.
// When constructed from an <linkto class=ImageExpr>ImageExpr</linkto>
// the mask is not persistent.
// </note>
// </synopsis>
 
// <example>
// </example>
 
// <motivation>
// Users must be able to specify a mask based on an expression.
// </motivation>
 
// # <todo asof="1998/05/20">
// #   <li>
// # </todo>
 
class WCLELMask : public WCRegion {
 public:
  WCLELMask();
 
  // Construct from the given expression command.
  // The command will be parsed and converted to an ImageExpr.
  // <group>
  explicit WCLELMask(const String& command);
  explicit WCLELMask(const char* command);
  // </group>
 
  // Construct from the given image expression.
  explicit WCLELMask(const ImageExpr<Bool>& expr);
 
  // Construct from the given lattice expression.
  explicit WCLELMask(const LatticeExpr<Bool>& expr);
 
  // Construct from the given lattice expression.
  // This constructor makes it possible to have an expression with an
  // unknown shape (e.g. using LEL function INDEXIN).
  // If the shape is known, the LatticeExprNode will be converted to
  // a LatticeExpr<Bool>.
  explicit WCLELMask(const LatticeExprNode& expr);
 
  // Copy constructor (copy semantics).
  WCLELMask(const WCLELMask& other);
 
  // Destructor
  virtual ~WCLELMask();
 
  // Assignment (copy semantics)
  WCLELMask& operator=(const WCLELMask& other);
 
  // Comparison
  virtual Bool operator==(const WCRegion& other) const;
 
  // Clone a WCLELMask object.
  virtual WCRegion* cloneRegion() const;
 
  // Get the dimensionality (i.e. the number of axes).
  virtual uInt ndim() const;
 
  // WCLELMask cannot extend a region.
  virtual Bool canExtend() const;
 
  // Convert to an LCRegion using the given new coordinate system and shape.
  // If the region has coordinates, the WCRegion implementation will
  // be called. Otherwise the LatticeExpr is returned after checking
  // that the shape matches.
  virtual LCRegion* toLCRegion(const CoordinateSystem& cSys, const IPosition& latticeShape) const;
 
  // Convert to an LCRegion using the supplied <src>CoordinateSystem</src>
  // and shape.
  // It checks that coordinates match and that axes are not swapped.
  virtual LCRegion* doToLCRegion(const CoordinateSystem& cSys, const IPosition& latticeShape,
                                 const IPosition& pixelAxesMap, const IPosition& outOrder) const;
 
  // Convert the WCLELMask object to a record.
  // The record can be used to make the object persistent.
  // The <src>tableName</src> argument can be used by derived
  // classes (e.g. LCPagedMask) to put very large objects.
  virtual TableRecord toRecord(const String& tableName) const;
 
  // Convert to a WCLELMask from a record.
  static WCLELMask* fromRecord(const TableRecord& rec, const String& tableName);
 
  // Returns WCLELMask
  static String className();
 
  // Return region type.  Returns the class name
  virtual String type() const;
 
  const ImageExpr<Bool>* getImageExpr() const { return itsImageExpr; }
 
 private:
  // Process the command.
  void processCommand();
 
  // Initialize as a LatticeExprNode if expression's shape is unknown.
  // Otherwise as a LatticeExpr<Bool> if coordinates are unknown.
  // Otherwise as an ImageExpr<Bool>.
  void init(const LatticeExprNode& expr);
 
  String itsCommand;
  ImageExpr<Bool>* itsImageExpr;
  LatticeExpr<Bool>* itsLattExpr;
  LatticeExprNode* itsLattNode;
};
 
}  // namespace casacore
 
#endif