ReduceCx.h

#ifndef PSCF_CPU_REDUCE_CX_H
#define PSCF_CPU_REDUCE_CX_H
 
/*
* PSCF - Polymer Self-Consistent Field
*
* Copyright 2015 - 2025, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include "Reduce.h"
#include <fftw3.h>
#include <complex.h>
 
// Forward declaration
namespace Util {
   template <typename T> class Array;
}
 
namespace Pscf {
 
   using namespace Util;
 
   /*
   * Functions that perform reductions on fftw_complex arrays.
   *
   * A reduction is any operation that involves reducing all of
   * the elements of one or more array to a single scalar, such as
   * a summation or inner product. Complex reduction results are
   * returned as values of type std::complex<double> because the
   * fftw_complex type is an alias for an array type double[2]
   * that cannot be returned by value.
   */
 
   namespace Reduce {

      std::complex<double> sum(Array<fftw_complex> const & a);

      std::complex<double> sum(Array<fftw_complex> const & a,
                               int begin, int end);

      std::complex<double> sumSq(Array<fftw_complex> const & a);

      std::complex<double> sumProduct(Array<fftw_complex> const & a,
                                      Array<fftw_complex> const & b);
 
   } // namespace Reduce
} // namespace Pscf
#endif