separate gamma2

Author: ChrisRackauckas

src/odenlstep.jl

@@ -9,27 +9,14 @@ struct ODENLStepData{NLProb, UNLProb, SetGammaC, SetOuterTmp, SetInnerTmp, NLPro
     implicit time discretizations. This allows to use extra structure of the ODE function (e.g.
     multi-level structure). The nonlinear function must match that form of the function implicit
     ODE integration algorithms need do solve the a nonlinear problems,
-    specifically of the form `M*z = outer_tmp + γ⋅f(z+inner_tmp,p,t_c)`.
+    specifically of the form `M*z = outer_tmp + γ₁⋅f(γ₂⋅z+inner_tmp,p,t_c)`.
     Here `z` is the stage solution vector, `p` is the parameter of the ODE problem, `t_c` is
-    the time of evaluation (`t_c = t + c*dt`), `γ` is some scaling factor and the temporary
-    variables are some compatible vectors set by the specific solver.
-    Note that this field will not be used for integrators such as fully-implicit Runge-Kutta methods
-    that need to solve different nonlinear systems.
-    The inner nonlinear function of the nonlinear problem is in general of the form `g(z,p') = 0`
-    where `p'` is a NamedTuple with all information about the specific nonlinear problem at hand to solve
-    for a specific time discretization. Specifically, it is `(;γ, inner_tmp, outer_tmp, t_c, p)`, such that
-    `g(z,p') = γ⋅f(z+inner_tmp,p,t_c) + outer_tmp - M*z = 0`.
+    the time of evaluation (`t_c = t + c*dt`), `γ₁` and `γ₂` are some scaling factors determined
+    by the solver algorithm and the temporary variables are some compatible vectors set by the specific solver.
+    The inner nonlinear function of the nonlinear problem is in general of the form `g(z,p') = 0` such that
+    `g(z,p') = γ₁⋅f(γ₂⋅z+inner_tmp,p,t_c) + outer_tmp - M*z = 0`.
     """
     nlprob::NLProb
-    """
-    A function which takes `(nlprob, value_provider)` and updates
-    the parameters of the former with their values in the latter.
-    If absent (`nothing`) this will not be called, and the parameters
-    in `nlprob` will be used without modification. `value_provider`
-    refers to a value provider as defined by SymbolicIndexingInterface.jl.
-    Usually this will refer to a problem or integrator.
-    """
-    update_nlprob!::UNLProb
     set_γ_c::SetGammaC
     set_outer_tmp::SetOuterTmp
     set_inner_tmp::SetInnerTmp