Merge pull request #2724 from SciML/relax

Don't check iszero Rational relax, instead make no-op

Author: ChrisRackauckas

lib/OrdinaryDiffEqNonlinearSolve/src/newton.jl

@@ -410,11 +410,16 @@ end
 function relax(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF) where {TF}
     relax(dz, nlsolver, integrator, f, relax(nlsolver))
 end
+function relax!(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
+        r::Nothing) where {TF}
+        dz
+end
 function relax!(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
         r::Number) where {TF}
     if !iszero(r)
         rmul!(dz, 1 - r)
     end
+    dz
 end
 
 function relax!(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
@@ -475,6 +480,11 @@ function relax(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
     return dz
 end
 
+function relax(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
+        r::Nothing) where {TF}
+    return dz
+end
+
 function relax(dz, nlsolver::AbstractNLSolver, integrator::DEIntegrator, f::TF,
         linesearch) where {TF}
     let dz = dz,

lib/OrdinaryDiffEqNonlinearSolve/src/type.jl

@@ -35,7 +35,7 @@ end
 
 function NLNewton(; κ = 1 // 100, max_iter = 10, fast_convergence_cutoff = 1 // 5,
         new_W_dt_cutoff = 1 // 5, always_new = false, check_div = true,
-        relax = 0 // 1)
+        relax = nothing)
     if relax isa Number && !(0 <= relax < 1)
         throw(ArgumentError("The relaxation parameter must be in [0, 1), got `relax = $relax`"))
     end
@@ -57,10 +57,6 @@ end
 function NonlinearSolveAlg(alg = NewtonRaphson(autodiff = AutoFiniteDiff());
         κ = 1 // 100, max_iter = 10, fast_convergence_cutoff = 1 // 5,
         new_W_dt_cutoff = 1 // 5, always_new = false, check_div = true)
-    if relax isa Number && !(0 <= relax < 1)
-        throw(ArgumentError("The relaxation parameter must be in [0, 1), got `relax = $relax`"))
-    end
-
     NonlinearSolveAlg(
         κ, max_iter, fast_convergence_cutoff, new_W_dt_cutoff, always_new, check_div,
         alg)

lib/OrdinaryDiffEqNonlinearSolve/src/utils.jl

@@ -229,7 +229,7 @@ function build_nlsolver(
                 end
                 nlp_params = (tmp, ustep, γ, α, tstep, k, invγdt, DIRK, p, dt, f)
             end
-            prob = NonlinearProblem(NonlinearFunction(nlf), ztmp, nlp_params)
+            prob = NonlinearProblem(NonlinearFunction{true}(nlf), ztmp, nlp_params)
             cache = init(prob, nlalg.alg)
             nlcache = NonlinearSolveCache(ustep, tstep, k, atmp, invγdt, prob, cache)
         else
@@ -313,7 +313,7 @@ function build_nlsolver(
                 end
                 nlp_params = (tmp, γ, α, tstep, invγdt, DIRK, p, dt, f)
             end
-            prob = NonlinearProblem(NonlinearFunction(nlf), copy(ztmp), nlp_params)
+            prob = NonlinearProblem(NonlinearFunction{false}(nlf), copy(ztmp), nlp_params)
             cache = init(prob, nlalg.alg)
             nlcache = NonlinearSolveCache(
                 nothing, tstep, nothing, nothing, invγdt, prob, cache)