text: //
  //   This file contains the C++ code from Program 14.18 of
  //   "Data Structures and Algorithms
  //    with Object-Oriented Design Patterns in C++"
  //   by Bruno R. Preiss.
  //
  //   Copyright (c) 1998 by Bruno R. Preiss, P.Eng.  All rights reserved.
  //
  //   http://www.pads.uwaterloo.ca/Bruno.Preiss/books/opus4/programs/pgm14_18.cpp
  //
  double SimpleRV::Sample ()
      { return RandomNumberGenerator::Next (); }
  
  double UniformRV::Sample ()
      { return u + (v - u) * RandomNumberGenerator::Next (); }
  
  double ExponentialRV::Sample ()
      { return -mu * std::log (RandomNumberGenerator::Next ()); }
  