const VariableGradient & Coupleable::coupledGradientPreviousNL(const std::string & var_name, unsigned int comp) { if (!isCoupled(var_name)) // Return default 0 return _default_gradient; _c_fe_problem.needsPreviousNewtonIteration(true); coupledCallback(var_name, true); if (_nodal) mooseError("Nodal variables do not have gradients"); MooseVariable * var = getVar(var_name, comp); if (!_coupleable_neighbor) return var->gradSlnPreviousNL(); else return var->gradSlnPreviousNLNeighbor(); }