NWTN

After NWTN Newton iterations the Jacobian is frozen, i.e., AUTO uses full Newton for the first NWTN iterations and the Chord method for iterations NWTN+1 to ITNW. The choice NWTN=3 is strongly recommended and used in most demos. Note that this constant is only effective for ODEs, i.e., for solving the piecewise polynomial collocation equations. For algebraic systems AUTO always uses full Newton.