average_order.hpp

/*******************************************************************************
 *
 * TRIQS: a Toolbox for Research in Interacting Quantum Systems
 *
 * Copyright (C) 2021, Simons Foundation
 *    author: N. Wentzell
 *
 * TRIQS 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.
 *
 * TRIQS 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
 * TRIQS. If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#pragma once
#include "../qmc_data.hpp"
 
namespace triqs_cthyb {

  struct measure_average_order {
 
    measure_average_order(qmc_data const &_data, double &_average_order) : data(_data), average_order(_average_order) { average_order = 0.0; }
 
    void accumulate(mc_weight_t) {
      average_order += data.config.size() / 2;
      ++N;
    }
 
    void collect_results(mpi::communicator const &comm) {
      N = mpi::all_reduce(N, comm);
 
      // Reduce and normalize
      average_order = mpi::all_reduce(average_order, comm);
      average_order = average_order / N;
    }
 
    private:
    // The Monte-Carlo configuration
    qmc_data const &data;
 
    // Reference to double for accumulation
    double &average_order;
 
    // Accumulation counter
    long long N = 0;
  };
 
} // namespace triqs_cthyb