integral_[ind], time_points_[ind + 1], time_points_[ind]);
double_update(&a_aux, time_points_[ind], sg_maxmin_precision * sg_surf_precision);
if (a_aux > 0)
integral_[ind], time_points_[ind + 1], time_points_[ind]);
double_update(&a_aux, time_points_[ind], sg_maxmin_precision * sg_surf_precision);
if (a_aux > 0)