epoc32/include/stdapis/boost/random/uniform_on_sphere.hpp
branchSymbian2
changeset 2 2fe1408b6811
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/epoc32/include/stdapis/boost/random/uniform_on_sphere.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,86 @@
     1.4 +/* boost random/uniform_on_sphere.hpp header file
     1.5 + *
     1.6 + * Copyright Jens Maurer 2000-2001
     1.7 + * Distributed under the Boost Software License, Version 1.0. (See
     1.8 + * accompanying file LICENSE_1_0.txt or copy at
     1.9 + * http://www.boost.org/LICENSE_1_0.txt)
    1.10 + *
    1.11 + * See http://www.boost.org for most recent version including documentation.
    1.12 + *
    1.13 + * $Id: uniform_on_sphere.hpp,v 1.11 2004/07/27 03:43:32 dgregor Exp $
    1.14 + *
    1.15 + * Revision history
    1.16 + *  2001-02-18  moved to individual header files
    1.17 + */
    1.18 +
    1.19 +#ifndef BOOST_RANDOM_UNIFORM_ON_SPHERE_HPP
    1.20 +#define BOOST_RANDOM_UNIFORM_ON_SPHERE_HPP
    1.21 +
    1.22 +#include <vector>
    1.23 +#include <algorithm>     // std::transform
    1.24 +#include <functional>    // std::bind2nd, std::divides
    1.25 +#include <boost/random/normal_distribution.hpp>
    1.26 +
    1.27 +namespace boost {
    1.28 +
    1.29 +template<class RealType = double, class Cont = std::vector<RealType> >
    1.30 +class uniform_on_sphere
    1.31 +{
    1.32 +public:
    1.33 +  typedef RealType input_type;
    1.34 +  typedef Cont result_type;
    1.35 +
    1.36 +  explicit uniform_on_sphere(int dim = 2) : _container(dim), _dim(dim) { }
    1.37 +
    1.38 +  // compiler-generated copy ctor and assignment operator are fine
    1.39 +
    1.40 +  void reset() { _normal.reset(); }
    1.41 +
    1.42 +  template<class Engine>
    1.43 +  const result_type & operator()(Engine& eng)
    1.44 +  {
    1.45 +    RealType sqsum = 0;
    1.46 +    for(typename Cont::iterator it = _container.begin();
    1.47 +        it != _container.end();
    1.48 +        ++it) {
    1.49 +      RealType val = _normal(eng);
    1.50 +      *it = val;
    1.51 +      sqsum += val * val;
    1.52 +    }
    1.53 +#ifndef BOOST_NO_STDC_NAMESPACE
    1.54 +    using std::sqrt;
    1.55 +#endif
    1.56 +    // for all i: result[i] /= sqrt(sqsum)
    1.57 +    std::transform(_container.begin(), _container.end(), _container.begin(),
    1.58 +                   std::bind2nd(std::divides<RealType>(), sqrt(sqsum)));
    1.59 +    return _container;
    1.60 +  }
    1.61 +
    1.62 +#if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
    1.63 +  template<class CharT, class Traits>
    1.64 +  friend std::basic_ostream<CharT,Traits>&
    1.65 +  operator<<(std::basic_ostream<CharT,Traits>& os, const uniform_on_sphere& sd)
    1.66 +  {
    1.67 +    os << sd._dim;
    1.68 +    return os;
    1.69 +  }
    1.70 +
    1.71 +  template<class CharT, class Traits>
    1.72 +  friend std::basic_istream<CharT,Traits>&
    1.73 +  operator>>(std::basic_istream<CharT,Traits>& is, uniform_on_sphere& sd)
    1.74 +  {
    1.75 +    is >> std::ws >> sd._dim;
    1.76 +    sd._container.resize(sd._dim);
    1.77 +    return is;
    1.78 +  }
    1.79 +#endif
    1.80 +
    1.81 +private:
    1.82 +  normal_distribution<RealType> _normal;
    1.83 +  result_type _container;
    1.84 +  int _dim;
    1.85 +};
    1.86 +
    1.87 +} // namespace boost
    1.88 +
    1.89 +#endif // BOOST_RANDOM_UNIFORM_ON_SPHERE_HPP