code_gen_fun_file.cpp

View page source

File Store and Retrieve a Code Gen Function: Example and Test

# include <cppad/example/code_gen_fun.hpp>

namespace {
   void store(const std::string& file_name)
   {  //
      typedef CppAD::cg::CG<double>     c_double;
      typedef CppAD::AD<c_double>      ac_double;
      typedef CppAD::vector<ac_double> ac_vector;
      //

      // domain space vector
      size_t n  = 2;
      ac_vector ac_x(n);
      for(size_t j = 0; j < n; ++j)
         ac_x[j] = 1.0 / double(j + 1);

      // declare independent variables and start tape recording
      CppAD::Independent(ac_x);

      // range space vector
      size_t m = 3;
      ac_vector ac_y(m);
      for(size_t i = 0; i < m; ++i)
         ac_y[i] = double(i + 1) * sin( ac_x[i % n] );

      // create c_f: x -> y and stop tape recording
      CppAD::ADFun<c_double> c_f(ac_x, ac_y);

      // create compiled version of c_f
      code_gen_fun f(file_name, c_f);
   }
}

bool file(void)
{  bool ok      = true;
   double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
   //
   // Store the compiled file in a dynamic link library
   std::string file_name = "example_lib";
   store(file_name);
   //
   // retrieve the compled function from the file
   // (compiling take much longer than retrieving the file)
   code_gen_fun f(file_name);

   // evaluate the compiled function
   size_t n = 2, m = 3;
   CppAD::vector<double> x(n), y(m);
   for(size_t j = 0; j < n; ++j)
      x[j] = 1.0 / double(j + 2);
   y = f(x);

   // check function values
   for(size_t i = 0; i < m; ++i)
   {  double check = double(i + 1) * std::sin( x[i % n] );
      ok &= CppAD::NearEqual(y[i] , check, eps99, eps99);
   }
   return ok;
}