code_gen_fun_file.cpp

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File Store and Retrieve a Code Gen Function: Example and Test

# include <cppad/example/code_gen_fun.hpp>

namespace {
    void store(const std::string& file_name)
    {   //
        typedef CppAD::cg::CG<double>     c_double;
        typedef CppAD::AD<c_double>      ac_double;
        typedef CppAD::vector<ac_double> ac_vector;
        //

        // 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
        code_gen_fun f(file_name, c_f);
    }
}

bool file(void)
{   bool ok      = true;
    double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
    //
    // Store the compiled file in a dynamic link library
    std::string file_name = "example_lib";
    store(file_name);
    //
    // retrieve the compled function from the file
    // (compiling take much longer than retrieving the file)
    code_gen_fun f(file_name);

    // evaluate the compiled function
    size_t n = 2, m = 3;
    CppAD::vector<double> 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;
}