cost_func.cpp

   1 #include <algorithm>
   2 #include <tr1/functional>
   3 #include <numeric>
   4 #include <iterator>
   5 #include <sstream>
   6 #include <stdexcept>
   7
   8 #include "cost_func.h"
   9
  10 cost_func::cost_func(const char* param)
  11 {
  12     std::istringstream paramstream(param);
  13     std::string token;
  14     while (std::getline(paramstream, token, ',')) {
  15         std::istringstream str(token);
  16         double f;
  17         if ((str >> f) && str.eof())
  18             factors.push_back(f);
  19         else
  20             throw std::invalid_argument("cost_func(): "
  21                                         "cannot parse \"" + token + "\"");
  22     }
  23     if (factors.empty())
  24         throw std::invalid_argument("cost_func(): no factor");
  25 }
  26
  27 cost_func::~cost_func()
  28 {
  29 }
  30
  31 double cost_func::operator()(double amount) const
  32 {
  33     using std::tr1::bind;
  34     using std::tr1::placeholders::_1;
  35     using std::tr1::placeholders::_2;
  36     return std::accumulate(++factors.begin(), factors.end(), factors.front(),
  37                            bind(std::plus<double>(),
  38                                 bind(std::multiplies<double>(), amount, _1),
  39                                 _2));
  40 }
  41
  42 std::string cost_func::to_string()
  43 {
  44     std::ostringstream oss;
  45     std::copy(factors.begin(), --factors.end(),
  46               std::ostream_iterator<double>(oss, ", "));
  47     oss << factors.back();
  48     return oss.str();
  49 }
  50
  51 // Local Variables:
  52 // mode: c++
  53 // End: