utils_random.h

Go to the documentation of this file.

/**
 *
 *   Copyright (c) 2005-2021 by Pierre-Henri WUILLEMIN(@LIP6) & Christophe GONZALES(@AMU)
 *   info_at_agrum_dot_org
 *
 *  This library is free software: you can 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  This library 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */


/**
 * @file
 * @brief Contains usefull methods for random stuff.
 *
 * @author Vincent RENAUDINEAU and Pierre-Henri WUILLEMIN(@LIP6)
 */

#ifndef GUM_UTILS_RANDOM_H
#define GUM_UTILS_RANDOM_H

#include <chrono>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <numeric>
#include <random>
#include <utility>
#include <vector>

#include <agrum/agrum.h>

namespace gum {

  /// @ingroup utilities_group
  /// @{

  /**
   * @brief Returns a random Idx between 0 and max-1 included.
   * @return Returns a random Odxbetween 0 and max-1 included (i.e. a proba).
   * By default, max=2
   */
  Idx randomValue(const Size max = 2);

  /**
   * @brief Returns a random double between 0 and 1 included (i.e. a proba).
   * @return Returns a random double between 0 and 1 included (i.e. a proba).
   */
  double randomProba();

  /**
   * @brief Return a random discrete distribution.
   * @param n The number of modalities for the ditribution.
   * @return Return a random discrete distribution.
   * @tparam GUM_SCALAR The type used for representing probabilities.
   */
  template < typename GUM_SCALAR >
  std::vector< GUM_SCALAR > randomDistribution(Size n);

  /**
   * @brief Returns the aGrUM's seed used by the std::generators.
   * @return Returns the aGrUM's seed used by the std::generators.
   */
  unsigned int randomGeneratorSeed();

  /**
   * @brief Initialize random generator seed.
   */
  void initRandom(unsigned int seed = 0);

  /**
   * define a random_engine with correct seed
   */
  std::default_random_engine getRandomGenerator(unsigned int seed = 0);

  /// @}
} /* namespace gum */

#ifndef GUM_NO_INLINE
#  include <agrum/tools/core/utils_random_inl.h>
#endif   // GUM_NO_INLINE

// always include the template implementations
#include <agrum/tools/core/utils_random_tpl.h>

#endif /* GUM_UTILS_RANDOM_H */