rem: cout << "# iter: " << iter << endl; cout << "# ratio: " << ratio << endl;
context: int main(){  int I,J;  I = J = 40;  pair<double, double> x(-4,4);  pair<double, double> y(-4,4);  boundary bound_f(boundary::DIRICHLET, J, 0.0);  boundary bound_f_odd(boundary::DIRICHLET, J, 1.0);  laplace fine(I, J, x, y, bound_f, bound_f, bound_f, bound_f_odd);    double norm_c0 = residual_norm::norm(fine);  int iter = multi(fine);  double norm_c1 = residual_norm::norm(fine);  double ratio = norm_c1/norm_c0;  /*  boundary bound_c(boundary::DIRICHLET, J/2, 0.0);  boundary bound_c_odd(boundary::DIRICHLET, J/2, 1.0);  laplace coarse(I/2, J/2, x, y, bound_c, bound_c, bound_c, bound_c_odd);  half_weighting hw;  hw(fine, coarse);  */  cout.precision(3);  cout << "# iter: " << iter << endl;  cout << "# ratio: " << ratio << endl;  //cout << coarse << endl;  cout << fine << endl;  return 0;}