# include <cppad/utility/speed_test.hpp>
# include <cppad/utility/vector.hpp>

namespace { // empty namespace
     using CppAD::vector;
     vector<double> a, b, c;
     void test(size_t size, size_t repeat)
     {     // setup
          a.resize(size);
          b.resize(size);
          c.resize(size);
          size_t i  = size;;
          while(i)
          {     --i;
               a[i] = double(i);
               b[i] = double(2 * i);
               c[i] = 0.0;
          }
          // operations we are timing
          while(repeat--)
          {     i = size;;
               while(i)
               {     --i;
                    c[i] += std::sqrt(a[i] * a[i] + b[i] * b[i]);
               }
          }
     }
}
bool speed_test(void)
{     bool ok = true;

     // size of the test cases
     vector<size_t> size_vec(2);
     size_vec[0] = 40;
     size_vec[1] = 80;

     // minimum amount of time to run test
     double time_min = 0.5;

     // run the test cases
     vector<size_t> rate_vec(2);
     rate_vec = CppAD::speed_test(test, size_vec, time_min);

     // time per repeat loop (note counting setup or teardown)
     double time_0 = 1. / double(rate_vec[0]);
     double time_1 = 1. / double(rate_vec[1]);

     // for this case, time should be linear w.r.t size
     double check    = double(size_vec[1]) * time_0 / double(size_vec[0]);
     double rel_diff = (check - time_1) / time_1;
     ok             &= (std::fabs(rel_diff) <= .1);
     if( ! ok )
          std::cout << std::endl << "rel_diff = " << rel_diff << std::endl;

     a.clear();
     b.clear();
     c.clear();
     return ok;
}