\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)

jit_dynamic.cpp

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JIT With Dynamic Parameters: Example and Test

Source

# include <cstddef>
# include <iostream>
# include <fstream>
# include <map>

// DLL_EXT
# ifdef _WIN32
# define DLL_EXT ".dll"
# else
# define DLL_EXT ".so"
# endif

# include <cppad/cppad.hpp>
bool dynamic(void)
{  bool ok = true;
   //
   using CppAD::AD;
   using CppAD::ADFun;
   using CppAD::Independent;
   using CppAD::NearEqual;
   //
   // nx, ny
   size_t np = 2, nx = 2, ny = 1;
   //
   // f(x) = x_0 + x_1
   CPPAD_TESTVECTOR( AD<double> ) ap(np), ax(nx), ay(ny);
   ap[0] = 0.0;
   ap[1] = 1.0;
   ax[0] = 2.0;
   ax[1] = 4.0;
   Independent(ax, ap);
   ay[0] = ap[0] * cos(ax[0])  + ap[1] * sin(ax[1]);
   ADFun<double> f(ax, ay);
   f.function_name_set("f");
   //
   // csrc_file
   // created in std::filesystem::current_path
   std::string c_type    = "double";
   std::string csrc_file = "dynamic.c";
   std::ofstream ofs;
   ofs.open(csrc_file , std::ofstream::out);
   f.to_csrc(ofs, c_type);
   ofs.close();
   //
   // dll_file
   // created in std::filesystem::current_path
   std::string dll_file = "jit_dynamic" DLL_EXT;
   CPPAD_TESTVECTOR( std::string) csrc_files(1);
   csrc_files[0] = csrc_file;
   std::map< std::string, std::string > options;
   std::string err_msg = CppAD::create_dll_lib(dll_file, csrc_files, options);
   if( err_msg != "" )
   {  std::cerr << "jit_dynamic: err_msg = " << err_msg << "\n";
      return false;
   }
   // dll_linker
   CppAD::link_dll_lib dll_linker(dll_file, err_msg);
   if( err_msg != "" )
   {  std::cerr << "jit_dynamic: err_msg = " << err_msg << "\n";
      return false;
   }
   //
   // f_ptr
   std::string function_name = "cppad_jit_f";
   void* void_ptr = dll_linker(function_name, err_msg);
   if( err_msg != "" )
   {  std::cerr << "dynamic: err_msg = " << err_msg << "\n";
      return false;
   }
   //
   // jit_double
   using CppAD::jit_double;
   //
   // f_ptr
   jit_double f_ptr =
      reinterpret_cast<jit_double>(void_ptr);
   //
   // u, y, compare_change
   // y = f(u)
   size_t nu             = np + nx;
   size_t compare_change = 0;
   std::vector<double> u(nu), y(ny);
   u[0] = 0.3;  // p[0]
   u[1] = 0.5;  // p[0]
   u[2] = 0.7;  // x[0]
   u[3] = 0.9;  // x[1]
   f_ptr(nu, u.data(), ny, y.data(), &compare_change);
   //
   // ok
   ok &= compare_change == 0;
   //
   // ok
   // f(u) = p[0] * cos(x[0]) + p[1] * sin(x[1])
   double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
   double check = u[0] * std::cos(u[2]) + u[1] * std::sin(u[3]);
   ok &= NearEqual(y[0], check, eps99, eps99);
   //
   return ok;
}