C++ (Cpp) get_row_value Examples

Example #1

File: glpk_wrapper.cpp Project: jadecastro/dreal3

void glpk_wrapper::get_error_bounds(double * errors) {
    int n = domain.size();
    int * nbr_non_zero = new int[n];
    for (int i = 0; i < n; i++) {
        errors[i] = INFINITY;
        nbr_non_zero[i] = 0;
    }

    // get the error on the KKT condition
    int sol;
    if (solver_type == SIMPLEX || solver_type == EXACT) {
        sol = GLP_SOL;
    } else {
        sol = GLP_IPT;
    }

    double ae_max;  // largest absolute error
    int ae_ind;     // number of row (PE), column (DE), or variable (PB, DB) with the largest absolute error
    double re_max;  // largest relative error
    int re_ind;     // number of row (PE), column (DE), or variable (PB, DB) with the largest relative error

    // GLP_KKT_PE — check primal equality constraints
    glp_check_kkt(lp, sol, GLP_KKT_PE, &ae_max, &ae_ind, &re_max, &re_ind);

    // a sparse vector for the coeffs in the row
    int row_size = 1;
    int * row_idx = new int[n + 1];
    double * row_coeff = new double[n + 1];

    // PE
    //  gives the distance between the auxiliary var and A * strucutral variable
    int m = glp_get_num_rows(lp);
    for (int i = 1; i <= m ; ++i) {
        // get the coeffs for that constraint
        row_size = glp_get_mat_row(lp, i, row_idx, row_coeff);
        for (int j = 1; j <= row_size; j++) {
            int v = row_idx[j] - 1;  // GLPK indexing
            nbr_non_zero[v] += 1;
            int c = row_coeff[j];
            // relative error
            errors[v] = std::min(errors[v], get_row_value(i) * re_max / c);
            // absolute error
            errors[v] = std::min(errors[v], ae_max / c);
        }
    }

    // variables that don't matter
    for (int i = 0; i < n; i++) {
        if (nbr_non_zero[i] == 0) {
            errors[i] = 0;
        }
        DREAL_LOG_INFO << "glpk_wrapper::get_error_bounds: error for " << domain.get_name(i) << " is " << errors[i];
    }

    delete[] nbr_non_zero;
    delete[] row_idx;
    delete[] row_coeff;
}

Example #2

File: model_based_opt.cpp Project: martin-neuhaeusser/z3

bool model_based_opt::invariant(unsigned index, row const& r) {
    vector<var> const& vars = r.m_vars;
    for (unsigned i = 0; i < vars.size(); ++i) {
        // variables in each row are sorted and have non-zero coefficients
        PASSERT(i + 1 == vars.size() || vars[i].m_id < vars[i+1].m_id);
        PASSERT(!vars[i].m_coeff.is_zero());
        PASSERT(index == 0 || m_var2row_ids[vars[i].m_id].contains(index));
    }

    PASSERT(r.m_value == get_row_value(r));
    PASSERT(r.m_type != t_eq ||  r.m_value.is_zero());
    // values satisfy constraints
    PASSERT(index == 0 || r.m_type != t_lt ||  r.m_value.is_neg());
    PASSERT(index == 0 || r.m_type != t_le || !r.m_value.is_pos());
    PASSERT(index == 0 || r.m_type != t_mod || (mod(r.m_value, r.m_mod).is_zero()));
    return true;
}