timestep_control.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2010 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------


#ifndef dealii_time_step_control_h
#define dealii_time_step_control_h

#include <deal.II/base/smartpointer.h>
#include <deal.II/base/subscriptor.h>

#include <deal.II/lac/vector_memory.h>

#include <cstdio>

DEAL_II_NAMESPACE_OPEN

class ParameterHandler;

namespace Algorithms
{
  class TimestepControl : public Subscriptor
  {
  public:
    enum Strategy
    {
      uniform,
      doubling
    };

    TimestepControl(double start      = 0.,
                    double final      = 1.,
                    double tolerance  = 1.e-2,
                    double start_step = 1.e-2,
                    double print_step = -1.,
                    double max_step   = 1.);

    static void
    declare_parameters(ParameterHandler &param);
    void
    parse_parameters(ParameterHandler &param);

    double
    start() const;
    double
    final() const;
    double
    tolerance() const;
    double
    step() const;

    double
    now() const;

    bool
    advance();

    void
    start(double);
    void
    final(double);
    void
    tolerance(double);
    void strategy(Strategy);

    void
    start_step(const double step);

    void
    max_step(double);

    void
    restart();
    bool
    print();
    void
    file_name_format(const char *);
    const char *
    file_name_format();

  private:
    double   start_val;
    double   final_val;
    double   tolerance_val;
    Strategy strategy_val;
    double   start_step_val;
    double   max_step_val;
    double   min_step_val;
    double current_step_val;
    double step_val;

    double now_val;
    double print_step;
    double next_print_val;

    char format[30];
  };


  inline double
  TimestepControl::start() const
  {
    return start_val;
  }


  inline double
  TimestepControl::final() const
  {
    return final_val;
  }


  inline double
  TimestepControl::step() const
  {
    return current_step_val;
  }


  inline double
  TimestepControl::tolerance() const
  {
    return tolerance_val;
  }


  inline double
  TimestepControl::now() const
  {
    return now_val;
  }


  inline void
  TimestepControl::start(double t)
  {
    start_val = t;
  }


  inline void
  TimestepControl::final(double t)
  {
    final_val = t;
  }


  inline void
  TimestepControl::tolerance(double t)
  {
    tolerance_val = t;
  }


  inline void
  TimestepControl::strategy(Strategy t)
  {
    strategy_val = t;
  }


  inline void
  TimestepControl::start_step(const double t)
  {
    start_step_val = t;
  }


  inline void
  TimestepControl::max_step(double t)
  {
    max_step_val = t;
  }


  inline void
  TimestepControl::restart()
  {
    now_val          = start_val;
    step_val         = start_step_val;
    current_step_val = step_val;
    if (print_step > 0.)
      next_print_val = now_val + print_step;
    else
      next_print_val = now_val - 1.;
  }


  inline void
  TimestepControl::file_name_format(const char *fmt)
  {
    strcpy(format, fmt);
  }


  inline const char *
  TimestepControl::file_name_format()
  {
    return format;
  }
} // namespace Algorithms

DEAL_II_NAMESPACE_CLOSE

#endif