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fun_dynamic_xam.cpp

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C++: Using Dynamic Parameters: Example and Test

# include <cstdio>
# include <cppad/py/cppad_py.hpp>

bool fun_dynamic_xam(void) {
   using cppad_py::a_double;
   using cppad_py::vec_double;
   using cppad_py::vec_a_double;
   using cppad_py::d_fun;
   //
   // initialize return variable
   bool ok = true;
   //------------------------------------------------------------------------
   int nx = 2;
   int nd = 2;
   //
   // value of independent variables during recording
   vec_double x(nx);
   for(int i = 0; i < nx ; i++) {
      x[i] = i + 1.0;
   }
   //
   // value of independent dynamic parameters during recording
   vec_double dynamic(nd);
   for(int i = 0; i < nd ; i++) {
      dynamic[i] = i + x[nx-1] + 1.0;
   }
   vec_a_double a_both = cppad_py::independent(x, dynamic);
   //
   // extract vector of independent variables and dynamic parameters
   vec_a_double ax(nx), adynamic(nd);
   for(int i = 0; i < nx ; i++) {
      ax[i] = a_both[i];
   }
   for(int i = 0; i < nd ; i++) {
      adynamic[i] = a_both[nx + i];
   }
   //
   // create another dynamic paramerer
   a_double adyn  = adynamic[0] + adynamic[1];
   //
   // create another variable
   a_double avar  = ax[0] + ax[1] + adyn;
   //
   // create f(x) = x[0] + x[1] + dynamic[0] + dynamic[1]
   vec_a_double ay(1);
   ay[0] = avar;
   d_fun f(ax, ay);
   //
   // check some properties of f
   ok &= f.size_domain() == nx;
   ok &= f.size_order()  == 0;
   //
   // zero order forward mode using same values as during the recording
   vec_double y(1);
   y   = f.forward(0, x);
   ok &= y[0] == (x[0] + x[1] + dynamic[0] + dynamic[1]);
   //
   // zero order forward mode using different value for dynamic parameters
   dynamic[0] = dynamic[0] + 1.0;
   dynamic[1] = dynamic[1] + 1.0;
   f.new_dynamic(dynamic);
   y   = f.forward(0, x);
   ok &= y[0] == (x[0] + x[1] + dynamic[0] + dynamic[1]);
   //
   return( ok );
}