fftw.cc

// -*- mode: c++; fill-column: 80; c-basic-offset: 2; indent-tabs-mode: nil -*-
/*
    Copyright (c) 2010-2013 Juan Jose Garcia Ripoll

    Tensor 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 program 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 General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* MULTIDIMENSIONAL FAST FOURIER TRANSFORM */

#include <tensor/fftw.h>
#include <fftw3.h>
#include "fftw_common.hpp"

namespace tensor {

  const CTensor
  fftw(const CTensor &in, int direction)
  {
    CTensor out(in.dimensions());

    fftw_complex *pin =
            const_cast<fftw_complex*>
            (reinterpret_cast<const fftw_complex*> (in.begin()));
    fftw_complex *pout = reinterpret_cast<fftw_complex*> (out.begin());
    do_fftw(pin, pout, in.dimensions(), direction);

    return out;
  }

  const CTensor
  fftw(const CTensor& in, index dim, int direction) {
    assert(dim >=0 && dim < in.rank());
    CTensor out(in.dimensions());

    fftw_complex *pin =
            const_cast<fftw_complex*>
            (reinterpret_cast<const fftw_complex*> (in.begin()));
    fftw_complex *pout = reinterpret_cast<fftw_complex*> (out.begin());
    do_fftw(pin, pout, dim, in.dimensions(), direction);

    return out;
  }

  const CTensor
  fftw(const CTensor& in, const Booleans& convert, int direction) {
    assert(convert.size() == in.rank());
    CTensor out(in.dimensions());

    fftw_complex *pin =
      const_cast<fftw_complex*>
      (reinterpret_cast<const fftw_complex*> (in.begin()));
    fftw_complex *pout = reinterpret_cast<fftw_complex*> (out.begin());
    do_fftw(pin, pout, convert, in.dimensions(), direction);

    return out;
  }

} // namespace tensor