Merge pull request #2547 from AayushSabharwal/as/fix-io

fix: fix io handling in structural_simplify, input_output_handling tests

Author: ChrisRackauckas

src/systems/diffeqs/abstractodesystem.jl

@@ -870,12 +870,15 @@ function process_DEProblem(constructor, sys::AbstractODESystem, u0map, parammap;
         if eltype(u0map) <: Number
             u0map = unknowns(sys) .=> u0map
         end
+        if isempty(u0map)
+            u0map = Dict()
+        end
         initializeprob = ModelingToolkit.InitializationProblem(
             sys, t, u0map, parammap; guesses, warn_initialize_determined)
         initializeprobmap = getu(initializeprob, unknowns(sys))
 
-        zerovars = setdiff(unknowns(sys), keys(defaults(sys))) .=> 0.0
-        trueinit = identity.([zerovars; u0map])
+        zerovars = Dict(setdiff(unknowns(sys), keys(defaults(sys))) .=> 0.0)
+        trueinit = collect(merge(zerovars, eltype(u0map) <: Pair ? todict(u0map) : u0map))
         u0map isa StaticArraysCore.StaticArray &&
             (trueinit = SVector{length(trueinit)}(trueinit))
     else
@@ -913,7 +916,6 @@ function process_DEProblem(constructor, sys::AbstractODESystem, u0map, parammap;
         du0 = nothing
         ddvs = nothing
     end
-
     check_eqs_u0(eqs, dvs, u0; kwargs...)
 
     f = constructor(sys, dvs, ps, u0; ddvs = ddvs, tgrad = tgrad, jac = jac,

src/systems/systemstructure.jl

@@ -630,7 +630,7 @@ function _structural_simplify!(state::TearingState, io; simplify = false,
     if has_io
         ModelingToolkit.markio!(state, orig_inputs, io...)
     end
-    if io !== nothing || any(isinput, state.fullvars)
+    if io !== nothing
         state, input_idxs = ModelingToolkit.inputs_to_parameters!(state, io)
     else
         input_idxs = 0:-1 # Empty range

test/input_output_handling.jl

@@ -50,7 +50,7 @@ end
 @test !is_bound(sys31, sys1.v[2])
 
 # simplification turns input variables into parameters
-ssys = structural_simplify(sys)
+ssys, _ = structural_simplify(sys, ([u], []))
 @test ModelingToolkit.isparameter(unbound_inputs(ssys)[])
 @test !is_bound(ssys, u)
 @test u ∈ Set(unbound_inputs(ssys))
@@ -236,7 +236,7 @@ i = findfirst(isequal(u[1]), out)
 @variables x(t) u(t) [input = true]
 eqs = [D(x) ~ u]
 @named sys = ODESystem(eqs, t)
-@test_nowarn structural_simplify(sys)
+@test_nowarn structural_simplify(sys, ([u], []))
 
 #=
 ## Disturbance input handling

test/reduction.jl

@@ -234,7 +234,7 @@ eqs = [D(x) ~ σ * (y - x)
        u ~ z + a]
 
 lorenz1 = ODESystem(eqs, t, name = :lorenz1)
-lorenz1_reduced = structural_simplify(lorenz1)
+lorenz1_reduced, _ = structural_simplify(lorenz1, ([z], []))
 @test z in Set(parameters(lorenz1_reduced))
 
 # #2064

test/serialization.jl

@@ -65,4 +65,4 @@ probexpr = ODEProblemExpr{true}(ss, [capacitor.v => 0.0], (0, 0.1); observedfun_
 prob_obs = eval(probexpr)
 sol_obs = solve(prob_obs, ImplicitEuler())
 @show all_obs
-@test_broken sol_obs[all_obs] == sol[all_obs]
+@test sol_obs[all_obs] == sol[all_obs]

test/structural_transformation/tearing.jl

@@ -164,9 +164,10 @@ prob.f(du, u, pr, tt)
 @test du≈[u[2], u[1] + sin(u[2]) - pr * tt] atol=1e-5
 
 # test the initial guess is respected
-@named sys = ODESystem(eqs, t, defaults = Dict(z => Inf))
+@named sys = ODESystem(eqs, t, defaults = Dict(z => NaN))
 infprob = ODEProblem(structural_simplify(sys), [x => 1.0], (0, 1.0), [p => 0.2])
-@test_throws Any infprob.f(du, infprob.u0, pr, tt)
+infprob.f(du, infprob.u0, pr, tt)
+@test any(isnan, du)
 
 sol1 = solve(prob, RosShamp4(), reltol = 8e-7)
 sol2 = solve(ODEProblem{false}((u, p, t) -> [-asin(u[1] - pr * t)],