code_gen_fun_function.cpp

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Evaluate a Code Gen Function: Example and Test

# include <cppad/example/code_gen_fun.hpp>

bool function(void)
{   bool ok = true;
    //
    typedef CppAD::cg::CG<double>     c_double;
    typedef CppAD::AD<c_double>      ac_double;
    //
    typedef CppAD::vector<double>     d_vector;
    typedef CppAD::vector<ac_double> ac_vector;
    //
    double eps99 = 99.0 * std::numeric_limits<double>::epsilon();

    // domain space vector
    size_t n  = 2;
    ac_vector ac_x(n);
    for(size_t j = 0; j < n; ++j)
        ac_x[j] = 1.0 / double(j + 1);

    // declare independent variables and start tape recording
    CppAD::Independent(ac_x);

    // range space vector
    size_t m = 3;
    ac_vector ac_y(m);
    for(size_t i = 0; i < m; ++i)
        ac_y[i] = double(i + 1) * sin( ac_x[i % n] );

    // create c_f: x -> y and stop tape recording
    CppAD::ADFun<c_double> c_f(ac_x, ac_y);

    // create compiled version of c_f
    std::string file_name = "example_lib";
    code_gen_fun f(file_name, c_f);

    // evaluate the compiled function
    d_vector x(n), y(m);
    for(size_t j = 0; j < n; ++j)
        x[j] = 1.0 / double(j + 2);
    y = f(x);

    // check function values
    for(size_t i = 0; i < m; ++i)
    {   double check = double(i + 1) * std::sin( x[i % n] );
        ok &= CppAD::NearEqual(y[i] , check, eps99, eps99);
    }
    return ok;
}