MatrixIter.h

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// # MatrixIter.h: Iterate a matrix 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_MATRIXITER_2_H
#define CASA_MATRIXITER_2_H
 
#include "ArrayIter.h"
#include "Matrix.h"
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
//
// <summary> Iterate a Matrix cursor through another Array. </summary>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="" demos="">
// </reviewed>
//
// MatrixIterator steps a Matrix (the "cursor") through an array.
// 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
// matrix() member function which allows you to access the cursor as a Matrix.
//
// <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 want to make a "moment" map of a cube, i.e. collapse
// the "Z" axis by averaging it.
// <srcblock>
// Cube<float> cube;
// MatrixIterator planeIter(cube);
// Matrix<float> average(planeIter.matrix().copy()); // init with first plane
// planeIter.next(); // advance the iterator
// while (! planeIter.pastEnd()) {
//     average += planeIter.matrix(); // Sum the next plane
//     planeIter.next();
// }
// average /= float(cube.shape()(2));  // divide by the number of planes
// </srcblock>
 
template <typename T>
class MatrixIterator : public ArrayIterator<T> {
 public:
  // Iterate by matrices through array "a".
  // The first 2 axes form the cursor axes.
  explicit MatrixIterator(Array<T> &a);
 
  // Iterate by matrices through array "a".
  // The given axes form the cursor axes.
  MatrixIterator(Array<T> &a, size_t cursorAxis1, size_t cursorAxis2);
 
  // Return the matrix at the current position.
  Matrix<T> &matrix() { return *(Matrix<T> *)(this->ap_p.get()); }
 
 private:
  // Not implemented.
  MatrixIterator(const MatrixIterator<T> &) = delete;
  // Not implemented.
  MatrixIterator<T> &operator=(const MatrixIterator<T> &) = delete;
};
 
//
// <summary> Iterate a Matrix cursor through a R/O Array. </summary>
// <reviewed reviewer="UNKNOWN" date="before2004/08/25" tests="" demos="">
// </reviewed>
//
// ReadOnlyMatrixIterator behaves exactly like MatrixIterator (cf.) only
// it should be used on const Arrays.
//
// <note role=tip> Note that the R/O MatrixIterator is not derived from R/O
//        ArrayIterator.
// </note>
//
template <class T>
class ReadOnlyMatrixIterator {
 public:
  // <group>
  ReadOnlyMatrixIterator(const Array<T> &a) : mi(const_cast<Array<T> &>(a)) {}
 
  ReadOnlyMatrixIterator(const Array<T> &a, size_t cursorAxis1, size_t cursorAxis2)
      : mi(const_cast<Array<T> &>(a), cursorAxis1, cursorAxis2) {}
 
  void next() { mi.next(); }
  void reset() { mi.origin(); }
  void origin() { mi.origin(); }
 
  const Array<T> &array() { return mi.array(); }
  const Matrix<T> &matrix() { return mi.matrix(); }
 
  bool atStart() const { return mi.atStart(); }
  bool pastEnd() const { return mi.pastEnd(); }
  const IPosition &pos() const { return mi.pos(); }
  IPosition endPos() const { return mi.endPos(); }
  size_t ndim() const { return mi.ndim(); }
  // </group>
 private:
  // Not implemented.
  ReadOnlyMatrixIterator(const ReadOnlyMatrixIterator<T> &) = delete;
  // Not implemented.
  ReadOnlyMatrixIterator<T> &operator=(const ReadOnlyMatrixIterator<T> &) = delete;
 
  MatrixIterator<T> mi;
};
 
}  // namespace casacore
 
#include "MatrixIter.tcc"
 
#endif