graph_unary_op.cpp

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Graph Unary Operator: Example and Test

Source Code

# include <cppad/cppad.hpp>

bool unary_op(void)
{  bool ok = true;
   using std::string;
   double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
   //
   // AD graph example
   // node_1 : p[0]
   // node_2 : x[0]
   // node_3 : c[0]
   // node_4 : sin(p[0])
   // node_5 : sin(x[0])
   // node_6 : sin(c[0])
   // node_7 : sin(p[0]) + sin(x[0]) + sin(c[0])
   // y[0]   = sin(p[0]) + sin(x[0]) + sin(c[0])
   //
   // C++ graph object
   CppAD::cpp_graph graph_obj;
   //
   // operator being used
   CppAD::graph::graph_op_enum op_enum;
   //
   // set scalars
   graph_obj.function_name_set("unary_op example");
   size_t n_dynamic_ind = 1;
   graph_obj.n_dynamic_ind_set(n_dynamic_ind);
   size_t n_variable_ind = 1;
   graph_obj.n_variable_ind_set(n_variable_ind);
   graph_obj.constant_vec_push_back( -0.1 );
   //
   // node_4 : sin(p[0])
   op_enum = CppAD::graph::sin_graph_op;
   graph_obj.operator_vec_push_back(op_enum);
   graph_obj.operator_arg_push_back(1);
   //
   // node_5 : sin(x[0])
   graph_obj.operator_vec_push_back(op_enum);
   graph_obj.operator_arg_push_back(2);
   //
   // node_6 : sin(c[0])
   graph_obj.operator_vec_push_back(op_enum);
   graph_obj.operator_arg_push_back(3);
   //
   // node_7 : sin(p[0]) + sin(x[0]) + sin(c[0])
   //
   // n_arg comes before first_node
   graph_obj.operator_arg_push_back(3);
   // op_enum
   op_enum = CppAD::graph::sum_graph_op;
   graph_obj.operator_vec_push_back(op_enum);
   graph_obj.operator_arg_push_back(4);
   graph_obj.operator_arg_push_back(5);
   graph_obj.operator_arg_push_back(6);
   //
   // y[0]   = sin(p[0]) + sin(x[0]) + sin(c[0])
   graph_obj.dependent_vec_push_back(7);
   //
   // f(x, p) = sin(p_0) + sin(x_0) + sin(c_0)
   CppAD::ADFun<double> f;
   f.from_graph(graph_obj);
   ok &= f.Domain() == 1;
   ok &= f.Range() == 1;
   ok &= f.size_dyn_ind() == 1;
   //
   // value of constant in function
   CPPAD_TESTVECTOR(double) c(1);
   c[0] = -0.1;
   //
   // set independent variables and parameters
   CPPAD_TESTVECTOR(double) p(1), x(1);
   p[0] = 0.2;
   x[0] = 0.3;
   //
   // compute y = f(x, p)
   f.new_dynamic(p);
   CPPAD_TESTVECTOR(double) y = f.Forward(0, x);
   //
   // check result
   double check = std::sin(p[0]) + std::sin(x[0]) + std::sin(c[0]);
   ok &= CppAD::NearEqual(y[0], check, eps99, eps99);
   // -----------------------------------------------------------------------
   // Convert to Graph graph and back again
   f.to_graph(graph_obj);
   f.from_graph(graph_obj);
   // -----------------------------------------------------------------------
   //
   // compute y = f(x, p)
   f.new_dynamic(p);
   y = f.Forward(0, x);
   //
   // check result
   ok &= CppAD::NearEqual(y[0], check, eps99, eps99);
   //
   return ok;
}