LatticeFFT.h

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// # LatticeFFT.h: Definitions for Lattice FFT functions
// # Copyright (C) 1996,1997,1998,2003
// # 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
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#ifndef LATTICES_LATTICEFFT_H
#define LATTICES_LATTICEFFT_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/BasicSL/Complex.h>
#include <casacore/casa/Exceptions/Error.h>
#include <casacore/scimath/Mathematics/NumericTraits.h>
#include <casacore/casa/Arrays/ArrayFwd.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
template <class T>
class Lattice;
 
// <summary>Functions for Fourier transforming Lattices</summary>
 
// <reviewed reviewer="" date="" tests="" demos="">
// </reviewed>
 
// <prerequisite>
// </prerequisite>
 
// <etymology>
// </etymology>
 
// <synopsis>
// </synopsis>
 
// <example>
// <srcblock>
// </srcblock>
// </example>
 
// <motivation>
// </motivation>
 
// <todo asof="">
// </todo>
 
class LatticeFFT {
 public:
  // 2-D in-place complex->complex FFT. Transforms over the first two
  // dimensions and iterates over all the others. The Lattice must have two or
  // more dimensions otherwise an AipsError is thrown.
  template <class ComplexType>
  static void cfft2d(Lattice<ComplexType> &cLattice, const Bool toFrequency = True);
 
  // N-D in-place complex->complex FFT. Only transform over selected
  // dimensions. Iterate over the others. whichAxes must be the same length as
  // the number of dimensions in the Lattice otherwise an AipsError is thrown.
  template <class ComplexType>
  static void cfft(Lattice<ComplexType> &cLattice, const Vector<Bool> &whichAxes,
                   const Bool toFrequency = True);
 
  // Non-folded version
  template <class ComplexType>
  static void cfft0(Lattice<ComplexType> &cLattice, const Vector<Bool> &whichAxes,
                    const Bool toFrequency = True);
 
  // N-D in-place complex->complex FFT. Transform over all axes.
  template <class ComplexType>
  static void cfft(Lattice<ComplexType> &cLattice, const Bool toFrequency = True);
 
  // N-D real->complex FFT. Only one half of the Hermition result is
  // returned. Transforms are only done on selected dimensions. The origin of
  // the transform is the center of the Lattice ie., [nx/2,ny/2,...] if
  // doShift is True. Otherwise it is the first element ie., [0,0,...]
  template <class ComplexType>
  static void rcfft(Lattice<ComplexType> &out,
                    const Lattice<typename NumericTraits<ComplexType>::ConjugateType> &in,
                    const Vector<Bool> &whichAxes, const Bool doShift = True, Bool doFast = False);
 
  template <class ComplexType>
  static void myrcfft(Lattice<ComplexType> &out,
                      const Lattice<typename NumericTraits<ComplexType>::ConjugateType> &in,
                      const Vector<Bool> &whichAxes, const Bool doShift = True);
 
  // N-D real->complex FFT. Only one half of the Hermition result is
  // returned. Transform over all dimensions. The origin of
  // the transform is the center of the Lattice ie., [nx/2,ny/2,...] if
  // doShift is True. Otherwise it is the first element ie., [0,0,...]
  template <class ComplexType>
  static void rcfft(Lattice<ComplexType> &out,
                    const Lattice<typename NumericTraits<ComplexType>::ConjugateType> &in,
                    const Bool doShift = True, Bool doFast = False);
  template <class ComplexType>
  static void myrcfft(Lattice<ComplexType> &out,
                      const Lattice<typename NumericTraits<ComplexType>::ConjugateType> &in,
                      const Bool doShift = True);
 
  // N-D complex->real FFT. Only one half of the Hermition input is
  // required. If whichAxis is specified Transforms are only done on selected
  // dimensions otherwise they are done on all axes. The origin of the
  // transform is the center of the Lattice ie., [nx/2,ny/2,...] if doShift is
  // True, otherwise it is the first element ie., [0,0,...]
 
  // These functions will <b>scramble the input Lattice</b> unless the versions
  // with const inputs are used. The const input versions are less efficient as
  // they create a temporary Lattice and copy the input data into it.
  // <group>
  template <class ComplexType>
  static void crfft(Lattice<typename NumericTraits<ComplexType>::ConjugateType> &out,
                    Lattice<ComplexType> &in, const Vector<Bool> &whichAxes,
                    const Bool doShift = True, Bool doFast = False);
  template <class ComplexType>
  static void crfft(Lattice<typename NumericTraits<ComplexType>::ConjugateType> &out,
                    Lattice<ComplexType> &in, const Bool doShift = True, Bool doFast = False);
  template <class ComplexType>
  static void crfft(Lattice<typename NumericTraits<ComplexType>::ConjugateType> &out,
                    const Lattice<ComplexType> &in, const Bool doShift = True, Bool doFast = False);
  // </group>
};
 
// implement template specializations to throw exceptions in the relevant cases.
 
template <>
inline void LatticeFFT::cfft2d(Lattice<Float> &, const Bool) {
  ThrowCc(String(__func__) + ": This method does not support real-valued lattices");
}
 
template <>
inline void LatticeFFT::cfft2d(Lattice<Double> &, const Bool) {
  ThrowCc(String(__func__) + ": This method does not support real-valued lattices");
}
 
template <>
inline void LatticeFFT::cfft(Lattice<Float> &, const Vector<Bool> &, const Bool) {
  ThrowCc(String(__func__) + ": This method does not support real-valued lattices");
}
 
template <>
inline void LatticeFFT::cfft(Lattice<Double> &, const Vector<Bool> &, const Bool) {
  ThrowCc(String(__func__) + ": This method does not support real-valued lattices");
}
 
template <>
inline void LatticeFFT::rcfft(Lattice<Float> &, const Lattice<Complex> &, const Vector<Bool> &,
                              const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::rcfft(Lattice<Double> &, const Lattice<DComplex> &, const Vector<Bool> &,
                              const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::myrcfft(Lattice<Float> &, const Lattice<Complex> &, const Vector<Bool> &,
                                const Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::myrcfft(Lattice<Double> &, const Lattice<DComplex> &, const Vector<Bool> &,
                                const Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::rcfft(Lattice<Float> &, const Lattice<Complex> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::rcfft(Lattice<Double> &, const Lattice<DComplex> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::myrcfft(Lattice<Float> &, const Lattice<Complex> &, const Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::myrcfft(Lattice<Double> &, const Lattice<DComplex> &, const Bool) {
  ThrowCc(String(__func__) +
          ": This is the real -> complex version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<Complex> &, Lattice<Float> &, const Vector<Bool> &,
                              const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<DComplex> &, Lattice<Double> &, const Vector<Bool> &,
                              const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<Complex> &, Lattice<Float> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<DComplex> &, Lattice<Double> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<Complex> &, const Lattice<Float> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
template <>
inline void LatticeFFT::crfft(Lattice<DComplex> &, const Lattice<Double> &, const Bool, Bool) {
  ThrowCc(String(__func__) +
          ": This is the complex -> real version, you've "
          "called it with the wrong parameters");
}
 
}  // namespace casacore
#ifndef CASACORE_NO_AUTO_TEMPLATES
#include "LatticeFFT.tcc"
#endif  // # CASACORE_NO_AUTO_TEMPLATES
#endif