PointsRan.h

Go to the documentation of this file.

#ifndef POINTSRAN_H
#define POINTSRAN_H
/*
Generates random numbers according to array. See comments to this file/
 
 
Copyright (c) 2001 I. B. Smirnov
 
Permission to use, copy, modify, distribute and sell this file
and its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice, this permission notice,
and notices about any modifications of the original text
appear in all copies and in supporting documentation.
It is provided "as is" without express or implied warranty.
*/
 
#include "wcpplib/safetl/AbsArr.h"
 
/*
As far as I remember, this class generates random numbers
according to pointwise distribution, with linear interpolation
between given points and also with linear extrapolation
*/
 
class PointsRan {
 private:
  double xmin;           // is changed internally
  double xmax;           // is changed internally
  DynLinArr<double> x;   // x[0] is changed to xmin or that of zero
                         // intepolated y,
                         // x[q-1] to xmax or similarly zero y
  DynLinArr<double> y;   // y[0] and y[q-1] are recalculated correspondingly
  DynLinArr<double> iy;  // integrated minus initial level at xmin
  DynLinArr<double> a;
  double integ_total;
  double integ_active;
  double integ_start;
  int n_start;
  double integ_finish;
  int n_finish;
 
 public:
  PointsRan(void) { ; }
  PointsRan(DynLinArr<double> fx,  // passed by values, changed inside
            DynLinArr<double> fy,  // passed by values, changed inside
            double fxmin,          // minimum of generated distribution
            double fxmax);         // maximum of generated distribution
  // If minimum is less then x[0], the distribution is extended
  // by linear extraterpolation.
  // If the extrapolated line crosses zero, the extension stops right there.
  // Otherwise it stops at fxmin.
  // The same is done when xmax is more than x[q-1].
  // Thus xmin and xmax affects the shape of distribution and its integral.
 
  double ran(double flat_ran) const;
  double get_integ_total(void) const { return integ_total; }
  double get_integ_active(void) const { return integ_active; }
  // actual integral of active distribution
  void print(std::ostream& file) const;
};
 
#endif