LCEllipsoid.h

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// # LCEllipsoid.h: Define an N-dimensional ellipsoidal region of interest
// # Copyright (C) 1997,1998
// # 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_LCELLIPSOID_H
#define LATTICES_LCELLIPSOID_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/lattices/LRegions/LCRegionFixed.h>
#include <casacore/casa/Arrays/Vector.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Define an N-dimensional ellipsoidal region of interest.
// </summary>
 
// <use visibility=export>
 
// <reviewed reviewer="" date="" tests="">
// </reviewed>
 
// <prerequisite>
//   <li> <linkto class=LCRegion>LCRegion</linkto>
// </prerequisite>
 
// <synopsis>
// The LCEllipsoid class is a specialization of class
// <linkto class=LCRegion>LCRegion</linkto>.
// It makes it possible to define an N-dimensional ellipsoidal region
// of interest, which includes the border. A separate constructor exists
// to define the special case of an N-dimensional sphere.
// <br>
// The center and the radii of the ellipsoid do not need to be pixel aligned.
// The center of the ellipsoid may be outside the lattice.
// The current implementation only supports ellipsoids with axes parallel
// to the lattice axes except in the case of a 2-D ellipse for which a
// constructor is provided for specifying the angle between the x-axis
// and major axis of the ellipse.
// <p>
// It can only be used for a lattice of any dimensionality as long as the
// dimensionality of the (hyper-)ellipsoid matches the dimensionality of
// the lattice.
// </synopsis>
 
// <example>
// <srcblock>
// </srcblock>
// </example>
 
// <todo asof="1997/11/11">
// <li> Arguments to have ellipsoid axes not parallel to lattice axes for
// dimensions greater than 2. This is a nontrivial problem because of the
// complexity of the rotation matrices involved.
// </todo>
 
class LCEllipsoid : public LCRegionFixed {
 public:
  LCEllipsoid();
 
  // Construct an N-dimensional sphere with the given center and
  // radius (in pixels). The center is pixel-aligned.
  LCEllipsoid(const IPosition& center, Float radius, const IPosition& latticeShape);
 
  // Construct an N-dimensional sphere with the given center and
  // radius (in pixels). The center does not need to be pixel-aligned.
  // <group>
  LCEllipsoid(const Vector<Float>& center, Float radius, const IPosition& latticeShape);
  LCEllipsoid(const Vector<Double>& center, Double radius, const IPosition& latticeShape);
  // </group>
 
  // Construct an N-dimensional ellipsoid with the given center and
  // radii (in pixels). The center does not need to be pixel-aligned.
  // (the radii are half the length of the axes of the ellipsoid).
  // <group>
  LCEllipsoid(const Vector<Float>& center, const Vector<Float>& radii,
              const IPosition& latticeShape);
  LCEllipsoid(const Vector<Double>& center, const Vector<Double>& radii,
              const IPosition& latticeShape);
  // </group>
 
  // Construct a two dimensional ellipse with theta being the angle from
  // the x-axis to the major axis of the ellipse in radians.
  LCEllipsoid(const Float xcenter, const Float ycenter, const Float majorAxis,
              const Float minorAxis, const Float theta, const IPosition& latticeShape);
 
  // Copy constructor (reference semantics).
  LCEllipsoid(const LCEllipsoid& other);
 
  virtual ~LCEllipsoid();
 
  // Assignment (copy semantics).
  LCEllipsoid& operator=(const LCEllipsoid& other);
 
  // Make a copy of the derived object.
  LCRegion* cloneRegion() const override;
 
  // Get the center.
  const Vector<Float>& center() const;
 
  // Get the radii.
  const Vector<Float>& radii() const;
 
  // Get the angle of the major axis of the ellipse relative to the x-axis
  // 2-D only, throws exception if ellipse is not 2-D.
  const Float& theta() const;
 
  // Get the class name (to store in the record).
  static String className();
 
  // Get the region type.  Returns className()
  String type() const override;
 
  // Convert the (derived) object to a record.
  TableRecord toRecord(const String& tableName) const override;
 
  // Convert correct object from a record.
  static LCEllipsoid* fromRecord(const TableRecord&, const String& tableName);
 
 protected:
  // Construct another LCBox (for e.g. another lattice) by moving
  // this one. It recalculates the bounding box.
  // A positive translation value indicates "to right".
  LCRegion* doTranslate(const Vector<Float>& translateVector,
                        const IPosition& newLatticeShape) const override;
 
 private:
  // Comparison
  Bool equals(const LCRegion& other) const override;
 
  // Fill the itsCenter vector from an IPosition.
  void fillCenter(const IPosition& center);
 
  // Make the bounding box from center, radii, and shape.
  Slicer makeBox(const Vector<Float>& radii, const IPosition& latticeShape);
 
  // Define the mask to indicate which elements are inside the ellipsoid.
  void defineMask();
 
  // for 2-D ellipse with non-zero theta. Works for both cases center
  //  inside or outside the lattice.
  void _defineMask2D();
 
  // set the mask in the case the center lies outside the lattice
  void _doOutside();
 
  Vector<Float> itsCenter;
  Vector<Float> itsRadii;
  // small offset to guard against roundoff error
  Vector<Float> _epsilon;
  // for 2-D case only
  Float _theta;
  // is center inside the lattice?
  Bool _centerIsInside;
};
 
inline const Vector<Float>& LCEllipsoid::center() const { return itsCenter; }
inline const Vector<Float>& LCEllipsoid::radii() const { return itsRadii; }
 
}  // namespace casacore
 
#endif