uniformint_randomdev.h

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/*
 *  uniformint_randomdev.h
 *
 *  This file is part of NEST.
 *
 *  Copyright (C) 2004 The NEST Initiative
 *
 *  NEST 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  NEST 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 NEST.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef UNIFORMINT_RANDOMDEV_H
#define UNIFORMINT_RANDOMDEV_H

#include <cmath>
#include "randomgen.h"
#include "randomdev.h"
#include "lockptr.h"

/************************************************************/
/* Class UniformIntRNG                                      */
/*                                                          */
/* Generates an RNG which returns integer random numbers    */
/* uniformly distributed between two limits.                */
/*                                                          */
/* Arguments:                                               */
/*  - pointer to an RNG                                     */
/*                                                          */
/* Author:                                                  */
/*  Hans Ekkehard Plesser                                   */
/*                                                          */
/* History:                                                 */
/*  HEP, 2004-08-05                                         */
/*                                                          */
/************************************************************/

namespace librandom {

/*BeginDocumentation
Name: rdevdict::uniform_int - uniform integer random deviate generator
Description: Generates uniformly distributed integers between two given limits

  p(n) = 1 / (high - low + 1),   n = low, low+1, ..., high
    
Parameters: 
  low - smallest allowed random number
  high - largest allowed random number

SeeAlso: CreateRDV, RandomArray, rdevdict
Author: Hans Ekkehard Plesser
*/

  class UniformIntRandomDev : public RandomDev
  {

  public:

    // accept only lockPTRs for initialization,
    // otherwise creation of a lock ptr would 
    // occur as side effect---might be unhealthy
    UniformIntRandomDev(RngPtr r_in);
    UniformIntRandomDev();                // threaded

    using RandomDev::operator();
    using RandomDev::ldev;
    
    long ldev(RngPtr) const;   
    bool has_ldev() const { return true; }

    double operator()(RngPtr rthrd) const;   // threaded

    void set_status(const DictionaryDatum&);

    void get_status(DictionaryDatum&) const; 

  private:
    long nmin_;   
    long nmax_;   
    long range_;  
  };

  inline
  double UniformIntRandomDev::operator()(RngPtr rthrd) const
  {
    return static_cast<double>(ldev(rthrd)); 
  }

  inline 
  long UniformIntRandomDev::ldev(RngPtr r_s) const
  {
    assert(range_ > 0);
    return nmin_ + r_s->ulrand(range_);
  }
}

# endif