cost_func.cpp

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