VectorIter.h

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// # VectorIter.h: Iterate a vector cursor through another array
// # Copyright (C) 1993,1994,1995,1999
// # 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
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#ifndef CASA_VECTORITER_2_H
#define CASA_VECTORITER_2_H
 
#include "ArrayIter.h"
#include "Vector.h"
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
//
// <summary> Iterate an Vector cursor through another Array. </summary>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="" demos="">
// </reviewed>
//
// VectorIterator steps a Vector (the "cursor") through an array for the
// given axis.
// The cursor "refers" to storage in the array, so that changing the
// values in the cursor changes values in the original array.
//
// This class is derived from ArrayIterator; basically it only adds
// the vector() member function which allows you to access the cursor
// as a Vector.
//
// <note role=tip>
// The origin of the cursor, i.e. the subarray that moves through the
// larger array, is always zero.
// </note>
//
// In this example we sum all the elements of an array; of course we already
// have the "sum" function in ArrayMath.h that we should use instead.
//
// <srcblock>
// Array<float> af;
// // set af
// VectorIterator vi(af);
// float sum = 0.0;
// size_t n = vi.vector().nelements();
// while (! vi.pastEnd()) {
//     for (int i=0; i < n; i++) {   // N.B.; cursor always 0 based.
//         sum += vi.vector()(i);
//     }
//     vi.next();
// }
// </srcblock>
 
template <typename T>
class VectorIterator : public ArrayIterator<T> {
 public:
  // Iterate by vector cursors through array "a".
  // The vector cursor is taken for the given axis.
  explicit VectorIterator(Array<T> &a, size_t axis = 0);
 
  // Return a Vector at the current position.
  Vector<T> &vector() { return *(Vector<T> *)this->ap_p.get(); }
 
 private:
  // Not implemented.
  VectorIterator(const VectorIterator<T> &) = delete;
  // Not implemented.
  VectorIterator<T> &operator=(const VectorIterator<T> &) = delete;
};
 
//
// <summary> Iterate a Vector cursor through another Array. </summary>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="" demos="">
// </reviewed>
//
// ReadOnlyVectorIterator behaves exactly like VectorIterator (cf.) only
// it should be used on const Arrays.
//
// <note role=tip> Note that the R/O VectorIterator is not derived from R/O
//        ArrayIterator.
// </note>
 
template <typename T>
class ReadOnlyVectorIterator {
 public:
  // <group>
  explicit ReadOnlyVectorIterator(const Array<T> &a, size_t axis = 0)
      : vi(const_cast<Array<T> &>(a), axis) {}
 
  void next() { vi.next(); }
  void reset() { vi.origin(); }
  void origin() { vi.origin(); }
 
  const Array<T> &array() { return vi.array(); }
  const Vector<T> &vector() { return vi.vector(); }
 
  bool atStart() const { return vi.atStart(); }
  bool pastEnd() const { return vi.pastEnd(); }
  const IPosition &pos() const { return vi.pos(); }
  IPosition endPos() const { return vi.endPos(); }
  size_t ndim() const { return vi.ndim(); }
  // </group>
 private:
  // Not implemented.
  ReadOnlyVectorIterator(const ReadOnlyVectorIterator<T> &) = delete;
  // Not implemented.
  ReadOnlyVectorIterator<T> &operator=(const ReadOnlyVectorIterator<T> &) = delete;
 
  VectorIterator<T> vi;
};
 
}  // namespace casacore
 
#include "VectorIter.tcc"
 
#endif