SciML · avik-pal · Oct 4, 2024 · Sep 24, 2024 · Sep 26, 2024 · Sep 30, 2024
diff --git a/Project.toml b/Project.toml
@@ -1,7 +1,7 @@
 name = "NonlinearSolve"
 uuid = "8913a72c-1f9b-4ce2-8d82-65094dcecaec"
 authors = ["SciML"]
-version = "3.15.0-DEV"
+version = "3.15.0"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
@@ -14,6 +14,7 @@ FastClosures = "9aa1b823-49e4-5ca5-8b0f-3971ec8bab6a"
 FiniteDiff = "6a86dc24-6348-571c-b903-95158fe2bd41"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 LazyArrays = "5078a376-72f3-5289-bfd5-ec5146d43c02"
+LineSearch = "87fe0de2-c867-4266-b59a-2f0a94fc965b"
 LineSearches = "d3d80556-e9d4-5f37-9878-2ab0fcc64255"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 LinearSolve = "7ed4a6bd-45f5-4d41-b270-4a48e9bafcae"
@@ -79,11 +80,12 @@ Hwloc = "3"
 InteractiveUtils = "<0.0.1, 1"
 LazyArrays = "1.8.2, 2"
 LeastSquaresOptim = "0.8.5"
-LineSearches = "7.2"
+LineSearch = "0.1.2"
+LineSearches = "7.3"
 LinearAlgebra = "1.10"
 LinearSolve = "2.35"
 MINPACK = "1.2"
-MaybeInplace = "0.1.3"
+MaybeInplace = "0.1.4"
 ModelingToolkit = "9.41.0"
 NLSolvers = "0.5"
 NLsolve = "4.5"

diff --git a/docs/make.jl b/docs/make.jl
@@ -14,9 +14,11 @@ bib = CitationBibliography(joinpath(@__DIR__, "src", "refs.bib"))
 
 interlinks = InterLinks(
     "ADTypes" => "https://sciml.github.io/ADTypes.jl/stable/",
+    "LineSearch" => "https://sciml.github.io/LineSearch.jl/dev/"
 )
 
-makedocs(; sitename = "NonlinearSolve.jl",
+makedocs(;
+    sitename = "NonlinearSolve.jl",
     authors = "Chris Rackauckas",
     modules = [NonlinearSolve, SimpleNonlinearSolve, SteadyStateDiffEq,
         Sundials, DiffEqBase, SciMLBase, SciMLJacobianOperators],
@@ -30,6 +32,7 @@ makedocs(; sitename = "NonlinearSolve.jl",
     plugins = [bib, interlinks],
     format = Documenter.HTML(assets = ["assets/favicon.ico", "assets/citations.css"],
         canonical = "https://docs.sciml.ai/NonlinearSolve/stable/"),
-    pages)
+    pages
+)
 
 deploydocs(repo = "github.com/SciML/NonlinearSolve.jl.git"; push_preview = true)
diff --git a/docs/src/devdocs/internal_interfaces.md b/docs/src/devdocs/internal_interfaces.md
@@ -38,13 +38,6 @@ NonlinearSolve.AbstractDampingFunction
 NonlinearSolve.AbstractDampingFunctionCache
 ```
 
-## Line Search
-
-```@docs
-NonlinearSolve.AbstractNonlinearSolveLineSearchAlgorithm
-NonlinearSolve.AbstractNonlinearSolveLineSearchCache
-```
-
 ## Trust Region
 
 ```@docs

diff --git a/docs/src/native/globalization.md b/docs/src/native/globalization.md
@@ -8,12 +8,9 @@ Pages = ["globalization.md"]
 
 ## [Line Search Algorithms](@id line-search)
 
-```@docs
-LiFukushimaLineSearch
-LineSearchesJL
-RobustNonMonotoneLineSearch
-NoLineSearch
-```
+Line Searches have been moved to an external package. Take a look at the
+[LineSearch.jl](https://github.com/SciML/LineSearch.jl) package and its
+[documentation](https://sciml.github.io/LineSearch.jl/dev/).
 
 ## Radius Update Schemes for Trust Region
 

diff --git a/docs/src/native/solvers.md b/docs/src/native/solvers.md
@@ -22,7 +22,7 @@ documentation.
     preconditioners. For more information on specifying preconditioners for LinearSolve
     algorithms, consult the
     [LinearSolve.jl documentation](https://docs.sciml.ai/LinearSolve/stable/).
-  - `linesearch`: the line search algorithm to use. Defaults to [`NoLineSearch()`](@ref),
+  - `linesearch`: the line search algorithm to use. Defaults to [`NoLineSearch()`](@extref LineSearch.NoLineSearch),
     which means that no line search is performed.  Algorithms from
     [`LineSearches.jl`](https://github.com/JuliaNLSolvers/LineSearches.jl/) must be
     wrapped in [`LineSearchesJL`](@ref) before being supplied. For a detailed documentation

diff --git a/src/NonlinearSolve.jl b/src/NonlinearSolve.jl
@@ -22,6 +22,8 @@ using LazyArrays: LazyArrays, ApplyArray, cache
 using LinearAlgebra: LinearAlgebra, ColumnNorm, Diagonal, I, LowerTriangular, Symmetric,
                      UpperTriangular, axpy!, cond, diag, diagind, dot, issuccess, istril,
                      istriu, lu, mul!, norm, pinv, tril!, triu!
+using LineSearch: LineSearch, AbstractLineSearchAlgorithm, AbstractLineSearchCache,
+                  NoLineSearch, RobustNonMonotoneLineSearch
 using LineSearches: LineSearches
 using LinearSolve: LinearSolve, LUFactorization, QRFactorization,
                    needs_concrete_A, AbstractFactorization,
@@ -172,8 +174,9 @@ export NewtonDescent, SteepestDescent, Dogleg, DampedNewtonDescent, GeodesicAcce
 
 # Globalization
 ## Line Search Algorithms
-export LineSearchesJL, NoLineSearch, RobustNonMonotoneLineSearch, LiFukushimaLineSearch
-export Static, HagerZhang, MoreThuente, StrongWolfe, BackTracking
+export LineSearchesJL, LiFukushimaLineSearch # FIXME: deprecated. use LineSearch.jl directly
+export Static, HagerZhang, MoreThuente, StrongWolfe, BackTracking  # FIXME: deprecated
+export NoLineSearch, RobustNonMonotoneLineSearch
 ## Trust Region Algorithms
 export RadiusUpdateSchemes
 

diff --git a/src/abstract_types.jl b/src/abstract_types.jl
@@ -106,22 +106,6 @@ function last_step_accepted(cache::AbstractDescentCache)
     return true
 end
 
-"""
-    AbstractNonlinearSolveLineSearchAlgorithm
-
-Abstract Type for all Line Search Algorithms used in NonlinearSolve.jl.
-
-### `__internal_init` specification
-
-```julia
-__internal_init(
-    prob::AbstractNonlinearProblem, alg::AbstractNonlinearSolveLineSearchAlgorithm, f::F,
-    fu, u, p, args...; internalnorm::IN = DEFAULT_NORM, kwargs...) where {F, IN} -->
-AbstractNonlinearSolveLineSearchCache
-```
-"""
-abstract type AbstractNonlinearSolveLineSearchAlgorithm end
-
 """
     AbstractNonlinearSolveLineSearchCache
 
@@ -512,9 +496,9 @@ SciMLBase.isinplace(::AbstractNonlinearSolveJacobianCache{iip}) where {iip} = ii
 abstract type AbstractNonlinearSolveTraceLevel end
 
 # Default Printing
-for aType in (AbstractTrustRegionMethod, AbstractNonlinearSolveLineSearchAlgorithm,
-    AbstractResetCondition, AbstractApproximateJacobianUpdateRule,
-    AbstractDampingFunction, AbstractNonlinearSolveExtensionAlgorithm)
+for aType in (AbstractTrustRegionMethod, AbstractResetCondition,
+    AbstractApproximateJacobianUpdateRule, AbstractDampingFunction,
+    AbstractNonlinearSolveExtensionAlgorithm)
     @eval function Base.show(io::IO, alg::$(aType))
         print(io, "$(nameof(typeof(alg)))()")
     end

diff --git a/src/algorithms/klement.jl b/src/algorithms/klement.jl
@@ -27,7 +27,7 @@ over this.
 function Klement(; max_resets::Int = 100, linsolve = nothing, alpha = nothing,
         linesearch = NoLineSearch(), precs = DEFAULT_PRECS,
         autodiff = nothing, init_jacobian::Val{IJ} = Val(:identity)) where {IJ}
-    if !(linesearch isa AbstractNonlinearSolveLineSearchAlgorithm)
+    if !(linesearch isa AbstractLineSearchAlgorithm)
         Base.depwarn(
             "Passing in a `LineSearches.jl` algorithm directly is deprecated. \
              Please use `LineSearchesJL` instead.", :Klement)

diff --git a/src/algorithms/pseudo_transient.jl b/src/algorithms/pseudo_transient.jl
@@ -1,7 +1,6 @@
 """
     PseudoTransient(; concrete_jac = nothing, linsolve = nothing,
-        linesearch::AbstractNonlinearSolveLineSearchAlgorithm = NoLineSearch(),
-        precs = DEFAULT_PRECS, autodiff = nothing)
+        linesearch = NoLineSearch(), precs = DEFAULT_PRECS, autodiff = nothing)
 
 An implementation of PseudoTransient Method [coffey2003pseudotransient](@cite) that is used
 to solve steady state problems in an accelerated manner. It uses an adaptive time-stepping
@@ -16,8 +15,8 @@ This implementation specifically uses "switched evolution relaxation"
     you are going to need more iterations to converge but it can be more stable.
 """
 function PseudoTransient(; concrete_jac = nothing, linsolve = nothing,
-        linesearch::AbstractNonlinearSolveLineSearchAlgorithm = NoLineSearch(),
-        precs = DEFAULT_PRECS, autodiff = nothing, alpha_initial = 1e-3)
+        linesearch = NoLineSearch(), precs = DEFAULT_PRECS, autodiff = nothing,
+        alpha_initial = 1e-3)
     descent = DampedNewtonDescent(; linsolve, precs, initial_damping = alpha_initial,
         damping_fn = SwitchedEvolutionRelaxation())
     return GeneralizedFirstOrderAlgorithm(;

diff --git a/src/core/approximate_jacobian.jl b/src/core/approximate_jacobian.jl
@@ -59,7 +59,7 @@ function ApproximateJacobianSolveAlgorithm{concrete_jac, name}(;
         linesearch = missing, trustregion = missing, descent, update_rule,
         reinit_rule, initialization, max_resets::Int = typemax(Int),
         max_shrink_times::Int = typemax(Int)) where {concrete_jac, name}
-    if linesearch !== missing && !(linesearch isa AbstractNonlinearSolveLineSearchAlgorithm)
+    if linesearch !== missing && !(linesearch isa AbstractLineSearchAlgorithm)
         Base.depwarn("Passing in a `LineSearches.jl` algorithm directly is deprecated. \
                       Please use `LineSearchesJL` instead.",
             :GeneralizedFirstOrderAlgorithm)
@@ -199,8 +199,8 @@ function SciMLBase.__init(
         if alg.linesearch !== missing
             supports_line_search(alg.descent) || error("Line Search not supported by \
                                                         $(alg.descent).")
-            linesearch_cache = __internal_init(
-                prob, alg.linesearch, f, fu, u, p; stats, internalnorm, kwargs...)
+            linesearch_cache = init(
+                prob, alg.linesearch, fu, u; stats, internalnorm, kwargs...)
             GB = :LineSearch
         end
 
@@ -317,7 +317,9 @@ function __step!(cache::ApproximateJacobianSolveCache{INV, GB, iip};
     if descent_result.success
         if GB === :LineSearch
             @static_timeit cache.timer "linesearch" begin
-                needs_reset, α = __internal_solve!(cache.linesearch_cache, cache.u, δu)
+                linesearch_sol = solve!(cache.linesearch_cache, cache.u, δu)
+                needs_reset = !SciMLBase.successful_retcode(linesearch_sol.retcode)
+                α = linesearch_sol.step_size
             end
             if needs_reset && cache.steps_since_last_reset > 5 # Reset after a burn-in period
                 cache.force_reinit = true

diff --git a/src/core/generalized_first_order.jl b/src/core/generalized_first_order.jl
@@ -66,7 +66,7 @@ function GeneralizedFirstOrderAlgorithm{concrete_jac, name}(;
             jacobian_ad !== nothing && ADTypes.mode(jacobian_ad) isa ADTypes.ReverseMode,
             jacobian_ad, nothing))
 
-    if linesearch !== missing && !(linesearch isa AbstractNonlinearSolveLineSearchAlgorithm)
+    if linesearch !== missing && !(linesearch isa AbstractLineSearchAlgorithm)
         Base.depwarn("Passing in a `LineSearches.jl` algorithm directly is deprecated. \
                       Please use `LineSearchesJL` instead.",
             :GeneralizedFirstOrderAlgorithm)
@@ -199,8 +199,17 @@ function SciMLBase.__init(
         if alg.linesearch !== missing
             supports_line_search(alg.descent) || error("Line Search not supported by \
                                                         $(alg.descent).")
-            linesearch_cache = __internal_init(
-                prob, alg.linesearch, f, fu, u, p; stats, internalnorm, kwargs...)
+            linesearch_ad = alg.forward_ad === nothing ?
+                            (alg.reverse_ad === nothing ? alg.jacobian_ad :
+                             alg.reverse_ad) : alg.forward_ad
+            if linesearch_ad !== nothing && iip && !DI.check_inplace(linesearch_ad)
+                @warn "$(linesearch_ad) doesn't support in-place problems."
+                linesearch_ad = nothing
+            end
+            linesearch_ad = get_concrete_forward_ad(
+                linesearch_ad, prob, False; check_forward_mode = false)
+            linesearch_cache = init(
+                prob, alg.linesearch, fu, u; stats, autodiff = linesearch_ad, kwargs...)
             GB = :LineSearch
         end
 
@@ -264,8 +273,9 @@ function __step!(cache::GeneralizedFirstOrderAlgorithmCache{iip, GB};
         cache.make_new_jacobian = true
         if GB === :LineSearch
             @static_timeit cache.timer "linesearch" begin
-                linesearch_failed, α = __internal_solve!(
-                    cache.linesearch_cache, cache.u, δu)
+                linesearch_sol = solve!(cache.linesearch_cache, cache.u, δu)
+                linesearch_failed = !SciMLBase.successful_retcode(linesearch_sol.retcode)
+                α = linesearch_sol.step_size
             end
             if linesearch_failed
                 cache.retcode = ReturnCode.InternalLineSearchFailed

diff --git a/src/core/spectral_methods.jl b/src/core/spectral_methods.jl
@@ -9,9 +9,8 @@ Method.
 
 ### Arguments
 
-  - `linesearch`: Globalization using a Line Search Method. This needs to follow the
-    [`NonlinearSolve.AbstractNonlinearSolveLineSearchAlgorithm`](@ref) interface. This
-    is not optional currently, but that restriction might be lifted in the future.
+  - `linesearch`: Globalization using a Line Search Method. This is not optional currently,
+    but that restriction might be lifted in the future.
   - `σ_min`: The minimum spectral parameter allowed. This is used to ensure that the
     spectral parameter is not too small.
   - `σ_max`: The maximum spectral parameter allowed. This is used to ensure that the
@@ -119,7 +118,7 @@ end
 function SciMLBase.__init(prob::AbstractNonlinearProblem, alg::GeneralizedDFSane, args...;
         stats = empty_nlstats(), alias_u0 = false, maxiters = 1000,
         abstol = nothing, reltol = nothing, termination_condition = nothing,
-        internalnorm::F = DEFAULT_NORM, maxtime = nothing, kwargs...) where {F}
+        maxtime = nothing, kwargs...)
     timer = get_timer_output()
     @static_timeit timer "cache construction" begin
         u = __maybe_unaliased(prob.u0, alias_u0)
@@ -130,8 +129,7 @@ function SciMLBase.__init(prob::AbstractNonlinearProblem, alg::GeneralizedDFSane
         fu = evaluate_f(prob, u)
         @bb fu_cache = copy(fu)
 
-        linesearch_cache = __internal_init(prob, alg.linesearch, prob.f, fu, u, prob.p;
-            stats, maxiters, internalnorm, kwargs...)
+        linesearch_cache = init(prob, alg.linesearch, fu, u; stats, kwargs...)
 
         abstol, reltol, tc_cache = init_termination_cache(
             prob, abstol, reltol, fu, u_cache, termination_condition)
@@ -167,7 +165,9 @@ function __step!(cache::GeneralizedDFSaneCache{iip};
     end
 
     @static_timeit cache.timer "linesearch" begin
-        linesearch_failed, α = __internal_solve!(cache.linesearch_cache, cache.u, cache.du)
+        linesearch_sol = solve!(cache.linesearch_cache, cache.u, cache.du)
+        linesearch_failed = !SciMLBase.successful_retcode(linesearch_sol.retcode)
+        α = linesearch_sol.step_size
     end
 
     if linesearch_failed

diff --git a/src/default.jl b/src/default.jl
@@ -364,7 +364,9 @@ function RobustMultiNewton(::Type{T} = Float64; concrete_jac = nothing, linsolve
                 radius_update_scheme = RadiusUpdateSchemes.Bastin),
             NewtonRaphson(; concrete_jac, linsolve, precs, autodiff),
             NewtonRaphson(; concrete_jac, linsolve, precs,
-                linesearch = LineSearchesJL(; method = BackTracking()), autodiff),
+                linesearch = LineSearch.LineSearchesJL(;
+                    method = LineSearches.BackTracking()),
+                autodiff),
             TrustRegion(; concrete_jac, linsolve, precs,
                 radius_update_scheme = RadiusUpdateSchemes.NLsolve, autodiff),
             TrustRegion(; concrete_jac, linsolve, precs,
@@ -405,7 +407,9 @@ function FastShortcutNonlinearPolyalg(
         else
             algs = (NewtonRaphson(; concrete_jac, linsolve, precs, autodiff),
                 NewtonRaphson(; concrete_jac, linsolve, precs,
-                    linesearch = LineSearchesJL(; method = BackTracking()), autodiff),
+                    linesearch = LineSearch.LineSearchesJL(;
+                        method = LineSearches.BackTracking()),
+                    autodiff),
                 TrustRegion(; concrete_jac, linsolve, precs, autodiff),
                 TrustRegion(; concrete_jac, linsolve, precs,
                     radius_update_scheme = RadiusUpdateSchemes.Bastin, autodiff))
@@ -426,7 +430,9 @@ function FastShortcutNonlinearPolyalg(
                     SimpleKlement(),
                     NewtonRaphson(; concrete_jac, linsolve, precs, autodiff),
                     NewtonRaphson(; concrete_jac, linsolve, precs,
-                        linesearch = LineSearchesJL(; method = BackTracking()), autodiff),
+                        linesearch = LineSearch.LineSearchesJL(;
+                            method = LineSearches.BackTracking()),
+                        autodiff),
                     TrustRegion(; concrete_jac, linsolve, precs,
                         radius_update_scheme = RadiusUpdateSchemes.Bastin, autodiff))
             end
@@ -439,12 +445,15 @@ function FastShortcutNonlinearPolyalg(
             else
                 # TODO: This number requires a bit rigorous testing
                 start_index = u0_len !== nothing ? (u0_len ≤ 25 ? 4 : 1) : 1
-                algs = (Broyden(; autodiff),
+                algs = (
+                    Broyden(; autodiff),
                     Broyden(; init_jacobian = Val(:true_jacobian), autodiff),
                     Klement(; linsolve, precs, autodiff),
                     NewtonRaphson(; concrete_jac, linsolve, precs, autodiff),
                     NewtonRaphson(; concrete_jac, linsolve, precs,
-                        linesearch = LineSearchesJL(; method = BackTracking()), autodiff),
+                        linesearch = LineSearch.LineSearchesJL(;
+                            method = LineSearches.BackTracking()),
+                        autodiff),
                     TrustRegion(; concrete_jac, linsolve, precs, autodiff),
                     TrustRegion(; concrete_jac, linsolve, precs,
                         radius_update_scheme = RadiusUpdateSchemes.Bastin, autodiff))
@@ -480,7 +489,8 @@ function FastShortcutNLLSPolyalg(
                 linsolve, precs, disable_geodesic = Val(true), autodiff, kwargs...),
             TrustRegion(; concrete_jac, linsolve, precs, autodiff, kwargs...),
             GaussNewton(; concrete_jac, linsolve, precs,
-                linesearch = LineSearchesJL(; method = BackTracking()),
+                linesearch = LineSearch.LineSearchesJL(;
+                    method = LineSearches.BackTracking()),
                 autodiff, kwargs...),
             TrustRegion(; concrete_jac, linsolve, precs,
                 radius_update_scheme = RadiusUpdateSchemes.Bastin, autodiff, kwargs...),