C++ AD Graph Atomic Three Functions: Example and Test

graph_atom_op.cpp

@(@\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}} }@)@This is cppad-20221105 documentation. Here is a link to its current documentation . C++ AD Graph Atomic Three Functions: Example and Test
Source Code


# include <cppad/cppad.hpp>

bool atom_op(void)
{   bool ok = true;
    using std::string;
    // -----------------------------------------------------------------------
    // 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]
    //
    // 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("f(x; p)");
    size_t n_dynamic_ind = 1;
    graph_obj.n_dynamic_ind_set(n_dynamic_ind);
    size_t n_variable_ind = 2;
    graph_obj.n_variable_ind_set(n_variable_ind);
    //
    // node_4 : p[0] * x[0]
    op_enum = CppAD::graph::mul_graph_op;
    graph_obj.operator_vec_push_back(op_enum);
    graph_obj.operator_arg_push_back(1);
    graph_obj.operator_arg_push_back(2);
    //
    // node_5 : x[1] + p[0] * x[0]
    op_enum = CppAD::graph::add_graph_op;
    graph_obj.operator_vec_push_back(op_enum);
    graph_obj.operator_arg_push_back(3);
    graph_obj.operator_arg_push_back(4);
    //
    // y[0]   = x[1] + p[0] * x[0]
    graph_obj.dependent_vec_push_back(5);
    //
    // f(x, p) = x_1 + p_0 * x_0
    CppAD::ADFun<float> f;
    f.from_graph(graph_obj);
    //
    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 fucntion 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<float> 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])
    //
    graph_obj.initialize();
    //
    graph_obj.function_name_set("g(u; p, q)");
    n_dynamic_ind = 2;
    graph_obj.n_dynamic_ind_set(n_dynamic_ind);
    n_variable_ind = 2;
    graph_obj.n_variable_ind_set(n_variable_ind);
    //
    // node_5 : u[0] + q[0]
    op_enum = CppAD::graph::add_graph_op;
    graph_obj.operator_vec_push_back(op_enum);
    graph_obj.operator_arg_push_back(3);
    graph_obj.operator_arg_push_back(1);
    //
    // node_6 : u[1] + q[1]
    graph_obj.operator_vec_push_back(op_enum);
    graph_obj.operator_arg_push_back(4);
    graph_obj.operator_arg_push_back(2);
    //
    // node_7 : f( u[0] + q[0], u[1] + q[1]; p)
    //
    // name_index, n_result, n_arg come before first_node
    size_t name_index = graph_obj.atomic_name_vec_size();
    graph_obj.atomic_name_vec_push_back("f(x; p)");
    //
    op_enum = CppAD::graph::atom_graph_op;
    graph_obj.operator_vec_push_back(op_enum);
    graph_obj.operator_arg_push_back(name_index);  // name_index
    graph_obj.operator_arg_push_back(1);           // n_result
    graph_obj.operator_arg_push_back(2);           // n_node_arg
    graph_obj.operator_arg_push_back(5);           // first node arg
    graph_obj.operator_arg_push_back(6);           // second node arg
    //
    // y[0]   = u[1] + q[1] + p[0] * (u[0]  + q[0])
    graph_obj.dependent_vec_push_back(7);
    // ------------------------------------------------------------------------
    CppAD::ADFun<float> g;
    g.from_graph(graph_obj);
    // ------------------------------------------------------------------------
    ok &= g.Domain() == 2;
    ok &= g.Range() == 1;
    ok &= g.size_dyn_ind() == 2;
    //
    // set p in g(u; p, q)
    CPPAD_TESTVECTOR(float) p(1);
    p[0] = 2.0;
    chk_f.new_dynamic(p);
    //
    // set q in g(u; p, q)
    CPPAD_TESTVECTOR(float) q(2);
    q[0] = 3.0;
    q[1] = 4.0;
    g.new_dynamic(q);
    //
    // evalute g(u; p, q)
    CPPAD_TESTVECTOR(float) 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]);
    // ------------------------------------------------------------------------
    g.to_graph(graph_obj);
    g.from_graph(graph_obj);
    // ------------------------------------------------------------------------
    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;
}

Input File: example/graph/atom_op.cpp