From f445f25d000b4dc2f3a4f2ee766029a9a3a21585 Mon Sep 17 00:00:00 2001
From: CompatHelper Julia <compathelper_noreply@julialang.org>
Date: Sun, 3 Nov 2024 20:15:29 +0000
Subject: [PATCH 1/5] CompatHelper: bump compat for SimpleNonlinearSolve to 2,
 (keep existing compat)

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index 69e498bc76..2dcb48233d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -136,7 +136,7 @@ Reexport = "1.0"
 SciMLBase = "2.53"
 SciMLOperators = "0.3"
 SciMLStructures = "1"
-SimpleNonlinearSolve = "1"
+SimpleNonlinearSolve = "1, 2"
 SimpleUnPack = "1"
 SparseDiffTools = "2"
 Static = "0.8, 1"

From 21a5a66e24f8dd6e8b0cdc2fe89617fa4794b2fd Mon Sep 17 00:00:00 2001
From: CompatHelper Julia <compathelper_noreply@julialang.org>
Date: Sun, 3 Nov 2024 22:15:12 +0000
Subject: [PATCH 2/5] CompatHelper: bump compat for NonlinearSolve to 4, (keep
 existing compat)

---
 Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project.toml b/Project.toml
index 69e498bc76..59e4c810a7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -96,7 +96,7 @@ LinearSolve = "2"
 Logging = "1.9"
 MacroTools = "0.5"
 MuladdMacro = "0.2.1"
-NonlinearSolve = "3"
+NonlinearSolve = "3, 4"
 OrdinaryDiffEqAdamsBashforthMoulton = "1"
 OrdinaryDiffEqBDF = "1"
 OrdinaryDiffEqCore = "1"

From e50bf9a4d2baf1111dc5d7dd2b3be4d9fba46d1a Mon Sep 17 00:00:00 2001
From: Shreyas Ekanathan <shreyase39@gmail.com>
Date: Wed, 13 Nov 2024 17:19:20 -0500
Subject: [PATCH 3/5] rename things and fix broadcast

---
 lib/OrdinaryDiffEqFIRK/src/algorithms.jl      |  4 ++--
 lib/OrdinaryDiffEqFIRK/src/controllers.jl     |  6 +++---
 lib/OrdinaryDiffEqFIRK/src/firk_caches.jl     | 19 ++++++++++++-------
 .../src/firk_perform_step.jl                  | 13 +++++++++----
 4 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/lib/OrdinaryDiffEqFIRK/src/algorithms.jl b/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
index 75ccae073c..ba45841ac6 100644
--- a/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
@@ -169,7 +169,7 @@ end
 
 function AdaptiveRadau(; chunk_size = Val{0}(), autodiff = Val{true}(),
      standardtag = Val{true}(), concrete_jac = nothing,
-     diff_type = Val{:forward}, min_stages = 3, max_stages = 7, 
+     diff_type = Val{:forward}, min_order = 5, max_order = 13, 
      linsolve = nothing, precs = DEFAULT_PRECS,
      extrapolant = :dense, fast_convergence_cutoff = 1 // 5,
      new_W_γdt_cutoff = 1 // 5,
@@ -187,6 +187,6 @@ function AdaptiveRadau(; chunk_size = Val{0}(), autodiff = Val{true}(),
      fast_convergence_cutoff,
      new_W_γdt_cutoff,
      controller,
-     step_limiter!, min_stages, max_stages)
+     step_limiter!, min_order, max_order)
 end
 
diff --git a/lib/OrdinaryDiffEqFIRK/src/controllers.jl b/lib/OrdinaryDiffEqFIRK/src/controllers.jl
index 6de40914d0..95816c8b32 100644
--- a/lib/OrdinaryDiffEqFIRK/src/controllers.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/controllers.jl
@@ -23,11 +23,11 @@ function step_accept_controller!(integrator, controller::PredictiveController, a
     hist_iter = hist_iter * 0.8 + iter * 0.2
     cache.hist_iter = hist_iter
     if (step > 10)
-        if (hist_iter < 2.6 && num_stages < alg.max_stages)
+        if (hist_iter < 2.6 && num_stages < (alg.max_order + 1) ÷ 2)
             cache.num_stages += 2
             cache.step = 1
             cache.hist_iter = iter
-        elseif ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > alg.min_stages)
+        elseif ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > (alg.min_order + 1) ÷ 2)
             cache.num_stages -= 2 
             cache.step = 1
             cache.hist_iter = iter
@@ -45,7 +45,7 @@ function step_reject_controller!(integrator, controller::PredictiveController, a
     hist_iter = hist_iter * 0.8 + iter * 0.2
     cache.hist_iter = hist_iter
     if (step > 10)
-        if ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > alg.min_stages)
+        if ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > (alg.min_order + 1) ÷ 2)
             cache.num_stages -= 2 
             cache.step = 1
             cache.hist_iter = iter
diff --git a/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl b/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
index 8dbcd690c7..e1dbe08ad8 100644
--- a/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
@@ -497,12 +497,12 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
         ::Val{false}) where {uEltypeNoUnits, uBottomEltypeNoUnits, tTypeNoUnits}
     uf = UDerivativeWrapper(f, t, p)
     uToltype = constvalue(uBottomEltypeNoUnits)
-    num_stages = alg.min_stages
-    max = alg.max_stages
+    max = (alg.max_order + 1) ÷ 2
+    num_stages = (alg.min_order + 1) ÷ 2
     tabs = [BigRadauIIA5Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA9Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA13Tableau(uToltype, constvalue(tTypeNoUnits))]
     
     i = 9
-    while i <= alg.max_stages
+    while i <= max
         push!(tabs, adaptiveRadauTableau(uToltype, constvalue(tTypeNoUnits), i))
         i += 2
     end
@@ -525,6 +525,8 @@ mutable struct AdaptiveRadauCache{uType, cuType, tType, uNoUnitsType, rateType,
     z::Vector{uType}
     w::Vector{uType}
     c_prime::Vector{tType}
+    αdt::Vector{tType}
+    βdt::Vector{tType}
     dw1::uType
     ubuff::uType
     dw2::Vector{cuType}
@@ -568,8 +570,8 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
     uf = UJacobianWrapper(f, t, p)
     uToltype = constvalue(uBottomEltypeNoUnits)
 
-    max = alg.max_stages
-    num_stages = alg.min_stages
+    max = (alg.max_order + 1) ÷ 2
+    num_stages = (alg.min_order + 1) ÷ 2
 
     tabs = [BigRadauIIA5Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA9Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA13Tableau(uToltype, constvalue(tTypeNoUnits))]
     i = 9
@@ -583,9 +585,12 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
     z = Vector{typeof(u)}(undef, max)
     w = Vector{typeof(u)}(undef, max)
     for i in 1 : max
-        z[i] = w[i] = zero(u)
+        z[i] = zero(u)
+        w[i] = zero(u)
     end
 
+    αdt = [zero(t) for i in 1:max]
+    βdt = [zero(t) for i in 1:max]
     c_prime = Vector{typeof(t)}(undef, max) #time stepping
     for i in 1 : max
         c_prime[i] = zero(t)
@@ -641,7 +646,7 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
     atol = reltol isa Number ? reltol : zero(reltol)
 
     AdaptiveRadauCache(u, uprev,
-        z, w, c_prime, dw1, ubuff, dw2, cubuff, dw, cont, derivatives, 
+        z, w, c_prime, αdt, βdt, dw1, ubuff, dw2, cubuff, dw, cont, derivatives, 
         du1, fsalfirst, ks, k, fw,
         J, W1, W2,
         uf, tabs, κ, one(uToltype), 10000, tmp,
diff --git a/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl b/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
index 5e42aa5b94..874d968cb6 100644
--- a/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
@@ -1598,7 +1598,7 @@ end
     @unpack num_stages, tabs = cache
     tab = tabs[(num_stages - 1) ÷ 2]
     @unpack T, TI, γ, α, β, c, e = tab
-    @unpack κ, cont, derivatives, z, w, c_prime = cache
+    @unpack κ, cont, derivatives, z, w, c_prime, αdt, βdt= cache
     @unpack dw1, ubuff, dw2, cubuff, dw = cache
     @unpack ks, k, fw, J, W1, W2 = cache
     @unpack tmp, atmp, jac_config, linsolve1, linsolve2, rtol, atol, step_limiter! = cache
@@ -1608,7 +1608,12 @@ end
     mass_matrix = integrator.f.mass_matrix
 
     # precalculations
-    γdt, αdt, βdt = γ / dt, α ./ dt, β ./ dt
+    γdt = γ / dt
+    for i in 1 : (num_stages - 1) ÷ 2
+        αdt[i] = α[i]/dt
+        βdt[i] = β[i]/dt
+    end
+
     (new_jac = do_newJ(integrator, alg, cache, repeat_step)) &&
         (calc_J!(J, integrator, cache); cache.W_γdt = dt)
     if (new_W = do_newW(integrator, alg, new_jac, cache.W_γdt))
@@ -1750,12 +1755,12 @@ end
         # transform `w` to `z`
         #mul!(z, T, w)
         for i in 1:num_stages - 1
-            z[i] = zero(u)
+            @.. z[i] = zero(u)
             for j in 1:num_stages
                 @.. z[i] += T[i,j] * w[j]
             end
         end
-        z[num_stages] = T[num_stages, 1] * w[1]
+        @.. z[num_stages] = T[num_stages, 1] * w[1]
         i = 2
         while i < num_stages
             @.. z[num_stages] += w[i]

From 937641f9cbf10234152a12300f82c1338ecbe1c1 Mon Sep 17 00:00:00 2001
From: Shreyas Ekanathan <shreyase39@gmail.com>
Date: Mon, 18 Nov 2024 21:31:51 -0500
Subject: [PATCH 4/5] speed ups

---
 lib/OrdinaryDiffEqFIRK/src/algorithms.jl      |  4 +-
 lib/OrdinaryDiffEqFIRK/src/controllers.jl     |  9 ++-
 lib/OrdinaryDiffEqFIRK/src/firk_caches.jl     | 39 ++++++++--
 .../src/firk_perform_step.jl                  | 75 +++++++++----------
 4 files changed, 75 insertions(+), 52 deletions(-)

diff --git a/lib/OrdinaryDiffEqFIRK/src/algorithms.jl b/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
index ba45841ac6..e98389ec7c 100644
--- a/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/algorithms.jl
@@ -163,8 +163,8 @@ struct AdaptiveRadau{CS, AD, F, P, FDT, ST, CJ, Tol, C1, C2, StepLimiter} <:
  new_W_γdt_cutoff::C2
  controller::Symbol
  step_limiter!::StepLimiter
- min_stages::Int
- max_stages::Int
+ min_order::Int
+ max_order::Int
 end
 
 function AdaptiveRadau(; chunk_size = Val{0}(), autodiff = Val{true}(),
diff --git a/lib/OrdinaryDiffEqFIRK/src/controllers.jl b/lib/OrdinaryDiffEqFIRK/src/controllers.jl
index 95816c8b32..3849d8114c 100644
--- a/lib/OrdinaryDiffEqFIRK/src/controllers.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/controllers.jl
@@ -22,12 +22,14 @@ function step_accept_controller!(integrator, controller::PredictiveController, a
     cache.step = step + 1
     hist_iter = hist_iter * 0.8 + iter * 0.2
     cache.hist_iter = hist_iter
+    max_stages = (alg.max_order - 1) ÷ 4 * 2 + 1
+    min_stages = (alg.min_order - 1) ÷ 4 * 2 + 1
     if (step > 10)
-        if (hist_iter < 2.6 && num_stages < (alg.max_order + 1) ÷ 2)
+        if (hist_iter < 2.6 && num_stages <= max_stages)
             cache.num_stages += 2
             cache.step = 1
             cache.hist_iter = iter
-        elseif ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > (alg.min_order + 1) ÷ 2)
+        elseif ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages >= min_stages)
             cache.num_stages -= 2 
             cache.step = 1
             cache.hist_iter = iter
@@ -44,8 +46,9 @@ function step_reject_controller!(integrator, controller::PredictiveController, a
     cache.step = step + 1
     hist_iter = hist_iter * 0.8 + iter * 0.2
     cache.hist_iter = hist_iter
+    min_stages = (alg.min_order - 1) ÷ 4 * 2 + 1
     if (step > 10)
-        if ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages > (alg.min_order + 1) ÷ 2)
+        if ((hist_iter > 8 || cache.status == VerySlowConvergence || cache.status == Divergence) && num_stages >= min_stages)
             cache.num_stages -= 2 
             cache.step = 1
             cache.hist_iter = iter
diff --git a/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl b/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
index e1dbe08ad8..b971b3cc4f 100644
--- a/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/firk_caches.jl
@@ -362,6 +362,10 @@ mutable struct RadauIIA9Cache{uType, cuType, uNoUnitsType, rateType, JType, W1Ty
     tmp4::uType
     tmp5::uType
     tmp6::uType
+    tmp7::uType
+    tmp8::uType
+    tmp9::uType
+    tmp10::uType
     atmp::uNoUnitsType
     jac_config::JC
     linsolve1::F1
@@ -440,6 +444,10 @@ function alg_cache(alg::RadauIIA9, u, rate_prototype, ::Type{uEltypeNoUnits},
     tmp4 = zero(u)
     tmp5 = zero(u)
     tmp6 = zero(u)
+    tmp7 = zero(u)
+    tmp8 = zero(u)
+    tmp9 = zero(u)
+    tmp10 = zero(u)
     atmp = similar(u, uEltypeNoUnits)
     recursivefill!(atmp, false)
     jac_config = build_jac_config(alg, f, uf, du1, uprev, u, tmp, dw1)
@@ -469,7 +477,7 @@ function alg_cache(alg::RadauIIA9, u, rate_prototype, ::Type{uEltypeNoUnits},
         du1, fsalfirst, k, k2, k3, k4, k5, fw1, fw2, fw3, fw4, fw5,
         J, W1, W2, W3,
         uf, tab, κ, one(uToltype), 10000,
-        tmp, tmp2, tmp3, tmp4, tmp5, tmp6, atmp, jac_config,
+        tmp, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmp10, atmp, jac_config,
         linsolve1, linsolve2, linsolve3, rtol, atol, dt, dt,
         Convergence, alg.step_limiter!)
 end
@@ -497,17 +505,26 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
         ::Val{false}) where {uEltypeNoUnits, uBottomEltypeNoUnits, tTypeNoUnits}
     uf = UDerivativeWrapper(f, t, p)
     uToltype = constvalue(uBottomEltypeNoUnits)
-    max = (alg.max_order + 1) ÷ 2
-    num_stages = (alg.min_order + 1) ÷ 2
+
+    max_order = alg.max_order
+    min_order = alg.min_order
+    max = (max_order - 1) ÷ 4 * 2 + 1
+    min = (min_order - 1) ÷ 4 * 2 + 1
+    if (alg.min_order < 5)
+        error("min_order choice $min_order below 5 is not compatible with the algorithm")
+    elseif (max < min)
+        error("max_order $max_order is below min_order $min_order")
+    end
+    num_stages = min
+
     tabs = [BigRadauIIA5Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA9Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA13Tableau(uToltype, constvalue(tTypeNoUnits))]
-    
     i = 9
     while i <= max
         push!(tabs, adaptiveRadauTableau(uToltype, constvalue(tTypeNoUnits), i))
         i += 2
     end
     cont = Vector{typeof(u)}(undef, max)
-    for i in 1: max
+    for i in 1:max
         cont[i] = zero(u)
     end
 
@@ -570,8 +587,16 @@ function alg_cache(alg::AdaptiveRadau, u, rate_prototype, ::Type{uEltypeNoUnits}
     uf = UJacobianWrapper(f, t, p)
     uToltype = constvalue(uBottomEltypeNoUnits)
 
-    max = (alg.max_order + 1) ÷ 2
-    num_stages = (alg.min_order + 1) ÷ 2
+    max_order = alg.max_order
+    min_order = alg.min_order
+    max = (max_order - 1) ÷ 4 * 2 + 1
+    min = (min_order - 1) ÷ 4 * 2 + 1
+    if (alg.min_order < 5)
+        error("min_order choice $min_order below 5 is not compatible with the algorithm")
+    elseif (max < min)
+        error("max_order $max_order is below min_order $min_order")
+    end
+    num_stages = min
 
     tabs = [BigRadauIIA5Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA9Tableau(uToltype, constvalue(tTypeNoUnits)), BigRadauIIA13Tableau(uToltype, constvalue(tTypeNoUnits))]
     i = 9
diff --git a/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl b/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
index 874d968cb6..2058c4fb15 100644
--- a/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
+++ b/lib/OrdinaryDiffEqFIRK/src/firk_perform_step.jl
@@ -1032,7 +1032,7 @@ end
     @unpack dw1, ubuff, dw23, dw45, cubuff1, cubuff2 = cache
     @unpack k, k2, k3, k4, k5, fw1, fw2, fw3, fw4, fw5 = cache
     @unpack J, W1, W2, W3 = cache
-    @unpack tmp, tmp2, tmp3, tmp4, tmp5, tmp6, atmp, jac_config, linsolve1, linsolve2, linsolve3, rtol, atol, step_limiter! = cache
+    @unpack tmp, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmp10, atmp, jac_config, linsolve1, linsolve2, linsolve3, rtol, atol, step_limiter! = cache
     @unpack internalnorm, abstol, reltol, adaptive = integrator.opts
     alg = unwrap_alg(integrator, true)
     @unpack maxiters = alg
@@ -1087,30 +1087,30 @@ end
         c2′ = c2 * c5′
         c3′ = c3 * c5′
         c4′ = c4 * c5′
-        z1 = @.. c1′ * (cont1 +
+        @.. z1 = c1′ * (cont1 +
                                 (c1′-c4m1) * (cont2 +
                                                      (c1′ - c3m1) * (cont3 +
                                                                             (c1′ - c2m1) * (cont4 + (c1′ - c1m1) * cont5))))
-        z2 = @.. c2′ * (cont1 +
+        @.. z2 = c2′ * (cont1 +
                                 (c2′-c4m1) * (cont2 +
                                                      (c2′ - c3m1) * (cont3 +
                                                                             (c2′ - c2m1) * (cont4 + (c2′ - c1m1) * cont5))))
-        z3 = @.. c3′ * (cont1 +
+        @.. z3 = c3′ * (cont1 +
                                 (c3′-c4m1) * (cont2 +
                                                      (c3′ - c3m1) * (cont3 +
                                                                             (c3′ - c2m1) * (cont4 + (c3′ - c1m1) * cont5))))
-        z4 = @.. c4′ * (cont1 +
+        @.. z4 = c4′ * (cont1 +
                                 (c4′-c4m1) * (cont2 +
                                                      (c4′ - c3m1) * (cont3 +
                                                                             (c4′ - c2m1) * (cont4 + (c4′ - c1m1) * cont5))))
-        z5 = @.. c5′ * (cont1 +
+        @.. z5 = c5′ * (cont1 +
                                 (c5′-c4m1) * (cont2 +
                                                      (c5′ - c3m1) * (cont3 + (c5′ - c2m1) * (cont4 + (c5′ - c1m1) * cont5))))
-        w1 = @.. broadcast=false TI11*z1+TI12*z2+TI13*z3+TI14*z4+TI15*z5
-        w2 = @.. broadcast=false TI21*z1+TI22*z2+TI23*z3+TI24*z4+TI25*z5
-        w3 = @.. broadcast=false TI31*z1+TI32*z2+TI33*z3+TI34*z4+TI35*z5
-        w4 = @.. broadcast=false TI41*z1+TI42*z2+TI43*z3+TI44*z4+TI45*z5
-        w5 = @.. broadcast=false TI51*z1+TI52*z2+TI53*z3+TI54*z4+TI55*z5
+        @.. w1 = TI11*z1+TI12*z2+TI13*z3+TI14*z4+TI15*z5
+        @.. w2 = TI21*z1+TI22*z2+TI23*z3+TI24*z4+TI25*z5
+        @.. w3 = TI31*z1+TI32*z2+TI33*z3+TI34*z4+TI35*z5
+        @.. w4 = TI41*z1+TI42*z2+TI43*z3+TI44*z4+TI45*z5
+        @.. w5 = TI51*z1+TI52*z2+TI53*z3+TI54*z4+TI55*z5
     end
 
     # Newton iteration
@@ -1328,21 +1328,21 @@ end
     if integrator.EEst <= oneunit(integrator.EEst)
         cache.dtprev = dt
         if alg.extrapolant != :constant
-            cache.cont1 = @.. (z4 - z5) / c4m1 # first derivative on [c4, 1]
-            tmp1 = @.. (z3 - z4) / c3mc4 # first derivative on [c3, c4]
-            cache.cont2 = @.. (tmp1 - cache.cont1) / c3m1 # second derivative on [c3, 1]
-            tmp2 = @.. (z2 - z3) / c2mc3 # first derivative on [c2, c3]
-            tmp3 = @.. (tmp2 - tmp1) / c2mc4 # second derivative on [c2, c4]
-            cache.cont3 = @.. (tmp3 - cache.cont2) / c2m1 # third derivative on [c2, 1]
-            tmp4 = @.. (z1 - z2) / c1mc2 # first derivative on [c1, c2]
-            tmp5 = @.. (tmp4 - tmp2) / c1mc3 # second derivative on [c1, c3]
-            tmp6 = @.. (tmp5 - tmp3) / c1mc4 # third derivative on [c1, c4]
-            cache.cont4 = @.. (tmp6 - cache.cont3) / c1m1 #fourth derivative on [c1, 1]
-            tmp7 = @.. z1 / c1 #first derivative on [0, c1]
-            tmp8 = @.. (tmp4 - tmp7) / c2 #second derivative on [0, c2]
-            tmp9 = @.. (tmp5 - tmp8) / c3 #third derivative on [0, c3]
-            tmp10 = @.. (tmp6 - tmp9) / c4 #fourth derivative on [0,c4]
-            cache.cont5 = @.. cache.cont4 - tmp10 #fifth derivative on [0,1]
+            @.. cache.cont1 = (z4 - z5) / c4m1 # first derivative on [c4, 1]
+            @.. tmp = (z3 - z4) / c3mc4 # first derivative on [c3, c4]
+            @.. cache.cont2 = (tmp - cache.cont1) / c3m1 # second derivative on [c3, 1]
+            @.. tmp2 = (z2 - z3) / c2mc3 # first derivative on [c2, c3]
+            @.. tmp3 = (tmp2 - tmp) / c2mc4 # second derivative on [c2, c4]
+            @.. cache.cont3 = (tmp3 - cache.cont2) / c2m1 # third derivative on [c2, 1]
+            @.. tmp4 = (z1 - z2) / c1mc2 # first derivative on [c1, c2]
+            @.. tmp5 = (tmp4 - tmp2) / c1mc3 # second derivative on [c1, c3]
+            @.. tmp6 = (tmp5 - tmp3) / c1mc4 # third derivative on [c1, c4]
+            @.. cache.cont4 = (tmp6 - cache.cont3) / c1m1 #fourth derivative on [c1, 1]
+            @.. tmp7 = z1 / c1 #first derivative on [0, c1]
+            @.. tmp8 = (tmp4 - tmp7) / c2 #second derivative on [0, c2]
+            @.. tmp9 = (tmp5 - tmp8) / c3 #third derivative on [0, c3]
+            @.. tmp10 = (tmp6 - tmp9) / c4 #fourth derivative on [0,c4]
+            @.. cache.cont5 = cache.cont4 - tmp10 #fifth derivative on [0,1]
         end
     end
 
@@ -1437,7 +1437,7 @@ end
         for i in 1 : num_stages
             z[i] = f(uprev + z[i], p, t + c[i] * dt)
         end
-        OrdinaryDiffEqCore.increment_nf!(integrator.stats, 5)
+        OrdinaryDiffEqCore.increment_nf!(integrator.stats, num_stages)
 
         #fw = TI * ff
         fw = Vector{typeof(u)}(undef, num_stages)
@@ -1619,7 +1619,7 @@ end
     if (new_W = do_newW(integrator, alg, new_jac, cache.W_γdt))
         @inbounds for II in CartesianIndices(J)
             W1[II] = -γdt * mass_matrix[Tuple(II)...] + J[II]
-            for i in 1 :(num_stages - 1) ÷ 2
+            for i in 1 : (num_stages - 1) ÷ 2
                 W2[i][II] = -(αdt[i] + βdt[i] * im) * mass_matrix[Tuple(II)...] + J[II]
             end
         end
@@ -1673,7 +1673,7 @@ end
             @.. tmp = uprev + z[i]
             f(ks[i], tmp, p, t + c[i] * dt)
         end
-        OrdinaryDiffEqCore.increment_nf!(integrator.stats, 5)
+        OrdinaryDiffEqCore.increment_nf!(integrator.stats, num_stages)
 
         #mul!(fw, TI, ks)
         for i in 1:num_stages
@@ -1700,15 +1700,12 @@ end
         @.. ubuff = fw[1] - γdt * Mw[1]
         needfactor = iter == 1 && new_W
 
-        linsolve1 = cache.linsolve1
         if needfactor
-            linres = dolinsolve(integrator, linsolve1; A = W1, b = _vec(ubuff), linu = _vec(dw1))
+            cache.linsolve1 = dolinsolve(integrator, linsolve1; A = W1, b = _vec(ubuff), linu = _vec(dw1)).cache
         else
-            linres = dolinsolve(integrator, linsolve1; A = nothing, b = _vec(ubuff), linu = _vec(dw1))
+            cache.linsolve1 = dolinsolve(integrator, linsolve1; A = nothing, b = _vec(ubuff), linu = _vec(dw1)).cache
         end
 
-        cache.linsolve1 = linres.cache
-
         for i in 1 :(num_stages - 1) ÷ 2
             @.. cubuff[i]=complex(
             fw[2 * i] - αdt[i] * Mw[2 * i] + βdt[i] * Mw[2 * i + 1], fw[2 * i + 1] - βdt[i] * Mw[2 * i] - αdt[i] * Mw[2 * i + 1])
@@ -1801,9 +1798,8 @@ end
         @.. broadcast=false ubuff=integrator.fsalfirst + tmp
 
         if alg.smooth_est
-            linres = dolinsolve(integrator, linres.cache; b = _vec(ubuff),
-                linu = _vec(utilde))
-            cache.linsolve1 = linres.cache
+            cache.linsolve1 = dolinsolve(integrator, linsolve1; b = _vec(ubuff),
+            linu = _vec(utilde)).cache
             integrator.stats.nsolve += 1
         end
 
@@ -1821,9 +1817,8 @@ end
             @.. broadcast=false ubuff=fsallast + tmp
 
             if alg.smooth_est
-                linres = dolinsolve(integrator, linres.cache; b = _vec(ubuff),
-                    linu = _vec(utilde))
-                cache.linsolve1 = linres.cache
+                cache.linsolve1 = dolinsolve(integrator, linsolve1; b = _vec(ubuff),
+                linu = _vec(utilde)).cache
                 integrator.stats.nsolve += 1
             end
 

From b6b86de50a9b8eec97f61ee109d1127c34463976 Mon Sep 17 00:00:00 2001
From: Shreyas Ekanathan <shreyase39@gmail.com>
Date: Tue, 19 Nov 2024 07:42:41 -0500
Subject: [PATCH 5/5] fix tests

---
 lib/OrdinaryDiffEqFIRK/test/ode_firk_tests.jl          | 6 +++---
 lib/OrdinaryDiffEqFIRKGenerator/test/ode_firk_tests.jl | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/OrdinaryDiffEqFIRK/test/ode_firk_tests.jl b/lib/OrdinaryDiffEqFIRK/test/ode_firk_tests.jl
index 72e0be40f4..cbbddf9467 100644
--- a/lib/OrdinaryDiffEqFIRK/test/ode_firk_tests.jl
+++ b/lib/OrdinaryDiffEqFIRK/test/ode_firk_tests.jl
@@ -17,10 +17,10 @@ sim21 = test_convergence(1 ./ 2 .^ (2.5:-1:0.5), prob_ode_2Dlinear, RadauIIA9())
 prob_ode_linear_big = remake(prob_ode_linear, u0 = big.(prob_ode_linear.u0), tspan = big.(prob_ode_linear.tspan))
 prob_ode_2Dlinear_big = remake(prob_ode_2Dlinear, u0 = big.(prob_ode_2Dlinear.u0), tspan = big.(prob_ode_2Dlinear.tspan))
 
-for i in [3, 5, 7], prob in [prob_ode_linear_big, prob_ode_2Dlinear_big]
+for i in [5, 9, 13], prob in [prob_ode_linear_big, prob_ode_2Dlinear_big]
     dts = 1 ./ 2 .^ (4.25:-1:0.25)
-    sim21 = test_convergence(dts, prob, AdaptiveRadau(min_stages = i, max_stages = i))
-    @test sim21.𝒪est[:final]≈ (2 * i - 1) atol=testTol
+    sim21 = test_convergence(dts, prob, AdaptiveRadau(min_order = i, max_order = i))
+    @test sim21.𝒪est[:final]≈ i atol=testTol
 end
 
 # test adaptivity
diff --git a/lib/OrdinaryDiffEqFIRKGenerator/test/ode_firk_tests.jl b/lib/OrdinaryDiffEqFIRKGenerator/test/ode_firk_tests.jl
index d3c19ebbb5..9b2c5b6ca8 100644
--- a/lib/OrdinaryDiffEqFIRKGenerator/test/ode_firk_tests.jl
+++ b/lib/OrdinaryDiffEqFIRKGenerator/test/ode_firk_tests.jl
@@ -6,8 +6,8 @@ testTol = 0.5
 prob_ode_linear_big = remake(prob_ode_linear, u0 = big.(prob_ode_linear.u0), tspan = big.(prob_ode_linear.tspan))
 prob_ode_2Dlinear_big = remake(prob_ode_2Dlinear, u0 = big.(prob_ode_2Dlinear.u0), tspan = big.(prob_ode_2Dlinear.tspan))
 
-for i in [9], prob in [prob_ode_linear_big, prob_ode_2Dlinear_big]
+for i in [17, 21], prob in [prob_ode_linear_big, prob_ode_2Dlinear_big]
     dts = 1 ./ 2 .^ (4.25:-1:0.25)
-    sim21 = test_convergence(dts, prob, AdaptiveRadau(min_stages = i, max_stages = i))
-    @test sim21.𝒪est[:final]≈ (2 * i - 1) atol=testTol
+    sim21 = test_convergence(dts, prob, AdaptiveRadau(min_order = i, max_order = i))
+    @test sim21.𝒪est[:final]≈ i atol=testTol
 end