unary_reduction.h

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/*
 *  This file is a part of TiledArray.
 *  Copyright (C) 2014  Virginia Tech
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Justus Calvin
 *  Department of Chemistry, Virginia Tech
 *
 *  unary_reduction.h
 *  Apr 2, 2014
 *
 */
 
#ifndef TILEDARRAY_TILE_OP_UNARY_REDUCTION_H__INCLUDED
#define TILEDARRAY_TILE_OP_UNARY_REDUCTION_H__INCLUDED
 
#include "TiledArray/tile_interface/trace.h"
#include <TiledArray/tile_op/tile_interface.h>
 
namespace TiledArray {
 
 
template <typename Tile>
class SumReduction {
 public:
  // typedefs
  using result_type = decltype(sum(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const { return result_type(0); }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result += arg;
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::sum;
    result += sum(arg);
  }
};  // class SumReduction
 
 
template <typename Tile>
class ProductReduction {
 public:
  // typedefs
  using result_type = decltype(product(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const { return result_type(1); }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result *= arg;
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::product;
    result *= product(arg);
  }
 
};  // class ProductReduction
 
 
template <typename Tile>
class TraceReduction {
 public:
  // typedefs
  using result_type = result_of_trace_t<Tile>;
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const { return result_type(0); }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result += arg;
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::trace;
    result += trace(arg);
  }
 
};  // class TraceReduction
 
 
template <typename Tile>
class SquaredNormReduction {
 public:
  // typedefs
  using result_type = decltype(squared_norm(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const { return result_type(0); }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result += arg;
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::squared_norm;
    result += squared_norm(arg);
  }
 
};  // class SquaredNormReduction
 
 
template <typename Tile, typename Enabler = void>
class MinReduction;
 
template <typename Tile>
class MinReduction<Tile, typename std::enable_if<detail::is_strictly_ordered<
                             detail::numeric_t<Tile>>::value>::type> {
 public:
  // typedefs
  using result_type = decltype(min(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const {
    return std::numeric_limits<result_type>::max();
  }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result = std::min(result, arg);
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::min;
    result = std::min(result, min(arg));
  }
 
};  // class MinReduction
 
 
template <typename Tile, typename Enabler = void>
class MaxReduction;
 
template <typename Tile>
class MaxReduction<Tile, typename std::enable_if<detail::is_strictly_ordered<
                             detail::numeric_t<Tile>>::value>::type> {
 public:
  // typedefs
  using result_type = decltype(max(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const {
    return std::numeric_limits<result_type>::min();
  }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result = std::max(result, arg);
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::max;
    result = std::max(result, max(arg));
  }
 
};  // class MaxReduction
 
 
template <typename Tile>
class AbsMinReduction {
 public:
  // typedefs
  using result_type = decltype(abs_min(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const {
    return std::numeric_limits<result_type>::max();
  }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result = std::min(result, std::abs(arg));
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::abs_min;
    result = std::min(result, abs_min(arg));
  }
 
};  // class AbsMinReduction
 
 
template <typename Tile>
class AbsMaxReduction {
 public:
  // typedefs
  using result_type = decltype(abs_max(std::declval<Tile>()));
  typedef Tile argument_type;
 
  // Reduction functions
 
  // Make an empty result object
  result_type operator()() const { return result_type(0); }
 
  // Post process the result
  const result_type& operator()(const result_type& result) const {
    return result;
  }
 
  // Reduce two result objects
  void operator()(result_type& result, const result_type& arg) const {
    result = std::max(result, std::abs(arg));
  }
 
  // Reduce an argument
  void operator()(result_type& result, const argument_type& arg) const {
    using TiledArray::abs_max;
    result = std::max(result, abs_max(arg));
  }
 
};  // class AbsMaxReduction
 
}  // namespace TiledArray
 
#endif  // TILEDARRAY_TILE_OP_UNARY_REDUCTION_H__INCLUDED