Пример #1
0
static void test_maximize(opt::model_based_opt& mbo, ast_manager& m, unsigned num_vars, expr_ref_vector const& fmls, app* t) {
    qe::arith_project_plugin plugin(m);
    model mdl(m);    
    arith_util a(m);
    for (unsigned i = 0; i < num_vars; ++i) {
        app_ref var(m);
        mk_var(i, var);
        rational val = mbo.get_value(i);
        mdl.register_decl(var->get_decl(), a.mk_numeral(val, false));
    }
    expr_ref ge(m), gt(m);
    opt::inf_eps value1 = plugin.maximize(fmls, mdl, t, ge, gt);
    opt::inf_eps value2 = mbo.maximize();    
    std::cout << "optimal: " << value1 << " " << value2 << "\n";
    mbo.display(std::cout);
}
Пример #2
0
static void add_ineq(opt::model_based_opt& mbo, 
                     unsigned x, int a, 
                     unsigned y, int b, int k, 
                     opt::ineq_type rel) {
    vector<var> vars;
    vars.push_back(var(x, rational(a)));
    vars.push_back(var(y, rational(b)));
    mbo.add_constraint(vars, rational(k), rel);
}
Пример #3
0
static void add_random_ineq(opt::model_based_opt& mbo,
                            random_gen& r,
                            svector<int>  const& values,
                            unsigned max_vars,
                            unsigned max_coeff) {
    unsigned num_vars = values.size();
    uint_set used_vars;
    vector<var> vars;
    int value = 0;
    for (unsigned i = 0; i < max_vars; ++i) {
        unsigned x = r(num_vars);
        if (used_vars.contains(x)) {
            continue;
        }
        used_vars.insert(x);
        int coeff = r(max_coeff + 1);
        if (coeff == 0) {
            continue;
        }
        unsigned sign = r(2);
		coeff = sign == 0 ? coeff : -coeff;
        vars.push_back(var(x, rational(coeff)));
        value += coeff*values[x];
    }
    unsigned abs_value = value < 0 ? - value : value;
    // value + k <= 0
    // k <= - value
    // range for k is 2*|value|
    // k <= - value - range
    opt::ineq_type rel = opt::t_le;

    int coeff = 0;
    if (r(4) == 0) {
        rel = opt::t_eq;
        coeff = -value;
    }
    else {
        if (abs_value > 0) {
            coeff = -value - r(2*abs_value);
        }
        else {
            coeff = 0;
        }
        if (coeff != -value && r(3) == 0) {
            rel = opt::t_lt;
        }   
    }
    mbo.add_constraint(vars, rational(coeff), rel);
}
Пример #4
0
static void add_random_ineq(
    expr_ref_vector& fmls, 
    opt::model_based_opt& mbo,
    random_gen& r,
    svector<int>  const& values,
    unsigned max_vars,
    unsigned max_coeff) 
{
    ast_manager& m = fmls.get_manager();
    arith_util a(m);

    unsigned num_vars = values.size();
    uint_set used_vars;
    vector<var_t> vars;
    int value = 0;
    for (unsigned i = 0; i < max_vars; ++i) {
        unsigned x = r(num_vars);
        if (used_vars.contains(x)) {
            continue;
        }
        used_vars.insert(x);
        int coeff = r(max_coeff + 1);
        if (coeff == 0) {
            continue;
        }
        unsigned sign = r(2);
        coeff = sign == 0 ? coeff : -coeff;
        vars.push_back(var_t(x, rational(coeff)));
        value += coeff*values[x];
    }
    unsigned abs_value = value < 0 ? - value : value;
    // value + k <= 0
    // k <= - value
    // range for k is 2*|value|
    // k <= - value - range
    opt::ineq_type rel = opt::t_le;

    int coeff = 0;
    if (r(4) == 0) {
        rel = opt::t_eq;
        coeff = -value;
    }
    else {
        if (abs_value > 0) {
            coeff = -value - r(2*abs_value);
        }
        else {
            coeff = 0;
        }
        if (coeff != -value && r(3) == 0) {
            rel = opt::t_lt;
        }   
    }
    expr_ref fml(m);
    app_ref t1(m);
    app_ref t2(a.mk_numeral(rational(0), a.mk_real()), m);
    mk_term(vars, rational(coeff), t1);
    switch (rel) {
    case opt::t_eq:
        fml = m.mk_eq(t1, t2);
        break;
    case opt::t_lt:
        fml = a.mk_lt(t1, t2);
        break;
    case opt::t_le:
        fml = a.mk_le(t1, t2);
        break;
    case opt::t_mod:
        NOT_IMPLEMENTED_YET();        
        break;        
    }
    fmls.push_back(fml);
    mbo.add_constraint(vars, rational(coeff), rel);
}