vpNoise.h

/****************************************************************************
 *
 * $Id: vpNoise.h 4649 2014-02-07 14:57:11Z fspindle $
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 2014 by INRIA. All rights reserved.
 * 
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * ("GPL") version 2 as published by the Free Software Foundation.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact INRIA about acquiring a ViSP Professional 
 * Edition License.
 *
 * See http://www.irisa.fr/lagadic/visp/visp.html for more information.
 * 
 * This software was developed at:
 * INRIA Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 * http://www.irisa.fr/lagadic
 *
 * If you have questions regarding the use of this file, please contact
 * INRIA at visp@inria.fr
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *
 * Description:
 * Generation of random number with uniform and normal probability density.
 *
 * Authors:
 * Eric Marchand
 *
 *****************************************************************************/


#ifndef vpNoise_hh
#define vpNoise_hh


#include <visp/vpConfig.h>


class VISP_EXPORT vpUniRand
{
    /*unsigned*/ long    a  ;
    /*unsigned*/ long    m ; //2^31-1
    /*unsigned*/ long    q ; //integer part of m/a
    /*unsigned*/ long    r ;//r=m mod a
    double    normalizer ; //we use a normalizer > m to ensure ans will never be 1 (it is the case if x = 739806647)

  private:
    void draw0();
  protected:
    long x;
    double draw1();

  public:
    vpUniRand(const long seed = 0)
      : a(16807), m(2147483647), q(127773), r(2836), normalizer(2147484721.0), x((seed)? seed : 739806647)
    {
    }
    virtual ~vpUniRand() {};

    double operator()() {return draw1();}

};

class vpGaussRand : public vpUniRand
{
  private :
    double mean;
    double sigma;
    double gaussianDraw();

  public:

    vpGaussRand() : vpUniRand(), mean(0), sigma(0) {}

    vpGaussRand(const double sigma_val, const double mean_val, const long noise_seed = 0)
      : vpUniRand(noise_seed), mean(mean_val), sigma(sigma_val) {}

    void setSigmaMean(const double sigma_val, const double mean_val) {
      this->mean = mean_val;
      this->sigma = sigma_val;
    }

    void seed(const long seed_val) {
      x=seed_val;
    }

    double operator()() {
      return sigma*gaussianDraw()+mean;
    }
};

#endif