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

json_atom_op.cpp

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Json Atomic Function Three Operator: Example and Test

Source Code

# include <cppad/cppad.hpp>

bool atom_op(void)
{  bool ok = true;
   using CppAD::vector;
   using CppAD::AD;
   // use single quote in graphs to avoid having to escape double quote
   //
   // -----------------------------------------------------------------------
   // Define f_0 (x_0, x_1; p) = x_1 + p_0 * x_0
   //
   // This function does not have an atomic function operator
   // node_1 : p[0]
   // node_2 : x[0]
   // node_3 : x[1]
   // node_4 : p[0] * x[0]
   // node_5 : x[1] + p[0] * x[0]
   // y[0]   = x[1] + p[0] * x[0]
   std::string json =
      "{\n"
      "   'function_name'  : 'f(x; p)',\n"
      "   'op_define_vec'  : [ 2, [\n"
      "       { 'op_code':1, 'name':'mul', 'n_arg':2 } ,\n"
      "       { 'op_code':2, 'name':'add', 'n_arg':2 } ]\n"
      "   ],\n"
      "   'n_dynamic_ind'  : 1,\n"         // p[0]
      "   'n_variable_ind' : 2,\n"         // x[0], x[1]
      "   'constant_vec'   : [ 0, [ ] ],\n"
      "   'op_usage_vec'   : [ 2, [\n"
      "       [ 1, 1, 2 ] ,\n" // p[0] * x[0]
      "       [ 2, 3, 4 ] ]\n" // x[1] + p[0] * x[0]
      "   ],\n"
      "   'dependent_vec' : [ 1, [5] ] \n"
      "}\n";
   // Convert the single quote to double quote
   for(size_t i = 0; i < json.size(); ++i)
      if( json[i] == '\'' ) json[i] = '"';
   //
   CppAD::ADFun<double> f;
   f.from_json(json);
   ok &= f.Domain() == 2;
   ok &= f.Range() == 1;
   ok &= f.size_dyn_ind() == 1;
   //
   // A ckhpoint_two function with name f(x; p) is derived from
   // an atomic_three function with the same name.
   bool internal_bool    = false;
   bool use_hes_sparsity = false;
   bool use_base2ad      = false;
   bool use_in_parallel  = false;
   CppAD::chkpoint_two<double> chk_f(f, "f(x; p)",
      internal_bool, use_hes_sparsity, use_base2ad, use_in_parallel
   );
   // -----------------------------------------------------------------------
   // g (u_0, u_1; p, q) = f(u_0 + q_0, u_1 + q_1, p)
   //                    = u_1 + q_1 + p_0 * ( u_0 + q_0 )
   //
   // This function has an atomic function operator with name f(x; p)
   // node_1 : q[0]
   // node_2 : q[1]
   // node_3 : u[0]
   // node_4 : u[1]
   // node_5 : u[0] + q[0]
   // node_6 : u[1] + q[1]
   // node_7 : f( u[0] + q[0], u[1] + q[1]; p)
   // y[0]   = u[1] + q[1] + p[0] * (u[0]  + q[0])
   json =
      "{\n"
      "   'function_name'  : 'g(u; p, q)',\n"
      "   'op_define_vec'  : [ 2, [\n"
      "       { 'op_code':1, 'name':'atom'           } ,\n"
      "       { 'op_code':2, 'name':'add', 'n_arg':2 } ]\n"
      "   ],\n"
      "   'n_dynamic_ind'  : 2,\n"              // q[0], q[1]
      "   'n_variable_ind' : 2,\n"              // u[0], u[1]
      "   'constant_vec'   : [ 0, [ ] ],\n"
      "   'op_usage_vec'   : [ 3, [\n"
      "       [ 2, 3, 1 ]                      ,\n" // u[0] + q[0]
      "       [ 2, 4, 2 ]                      ,\n" // u[1] + q[1]
      // f(u_0 + q_0, u_1 + q_1; p) =  u[1] + q[1] + p[0] * (u[0]  + q[0])
      "       [ 1, 'f(x; p)', 1, 2, [ 5, 6 ] ] ]\n"
      "   ],\n"
      "   'dependent_vec' : [ 1, [7] ] \n"
      "}\n";
   // Convert the single quote to double quote
   for(size_t i = 0; i < json.size(); ++i)
      if( json[i] == '\'' ) json[i] = '"';
   // ------------------------------------------------------------------------
   CppAD::ADFun<double> g;
   g.from_json(json);
   // ------------------------------------------------------------------------
   ok &= g.Domain() == 2;
   ok &= g.Range() == 1;
   ok &= g.size_dyn_ind() == 2;
   //
   // set p in g(u; p, q)
   vector<double> p(1);
   p[0] = 2.0;
   chk_f.new_dynamic(p);
   //
   // set q in g(u; p, q)
   vector<double> q(2);
   q[0] = 3.0;
   q[1] = 4.0;
   g.new_dynamic(q);
   //
   // evalute g(u; p, q)
   vector<double> u(2), y(1);
   u[0] = 5.0;
   u[1] = 6.0;
   y    = g.Forward(0, u);
   //
   // check value
   ok &= y[0] == u[1] + q[1] + p[0] * (u[0]  + q[0]);
   // ------------------------------------------------------------------------
   json = g.to_json();
   // std::cout << json;
   g.from_json(json);
   // ------------------------------------------------------------------------
   ok &= g.Domain() == 2;
   ok &= g.Range() == 1;
   ok &= g.size_dyn_ind() == 2;
   //
   // set p in g(u; p, q)
   p[0] = 3.0;
   chk_f.new_dynamic(p);
   //
   // set q in g(u; p, q)
   q[0] = 4.0;
   q[1] = 5.0;
   g.new_dynamic(q);
   //
   // evalute g(u; p, q)
   u[0] = 6.0;
   u[1] = 7.0;
   y    = g.Forward(0, u);
   //
   // check value
   ok &= y[0] == u[1] + q[1] + p[0] * (u[0]  + q[0]);
   // ------------------------------------------------------------------------
   return ok;
}