build: add MSL to test deps

Project.toml

@@ -68,6 +68,7 @@ Logging = "1.10"
 Makie = "0.20"
 Markdown = "1.10"
 ModelingToolkit = "8.75, 9"
+ModelingToolkitStandardLibrary = "2.7"
 PartialFunctions = "1.1"
 PrecompileTools = "1.2"
 Preferences = "1.3"
@@ -96,6 +97,7 @@ DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 DelayDiffEq = "bcd4f6db-9728-5f36-b5f7-82caef46ccdb"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"
+ModelingToolkitStandardLibrary = "16a59e39-deab-5bd0-87e4-056b12336739"
 OrdinaryDiffEq = "1dea7af3-3e70-54e6-95c3-0bf5283fa5ed"
 PartialFunctions = "570af359-4316-4cb7-8c74-252c00c2016b"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
@@ -111,4 +113,4 @@ UnicodePlots = "b8865327-cd53-5732-bb35-84acbb429228"
 Zygote = "e88e6eb3-aa80-5325-afca-941959d7151f"
 
 [targets]
-test = ["Pkg", "Plots", "UnicodePlots", "PyCall", "PythonCall", "SafeTestsets", "Test", "StaticArrays", "StochasticDiffEq", "Aqua", "Zygote", "PartialFunctions", "DataFrames", "ModelingToolkit", "OrdinaryDiffEq", "ForwardDiff"]
+test = ["Pkg", "Plots", "UnicodePlots", "PyCall", "PythonCall", "SafeTestsets", "Test", "StaticArrays", "StochasticDiffEq", "Aqua", "Zygote", "PartialFunctions", "DataFrames", "ModelingToolkit", "ModelingToolkitStandardLibrary", "OrdinaryDiffEq", "ForwardDiff"]

ext/SciMLBaseZygoteExt.jl

@@ -220,9 +220,7 @@ end
     function solu_adjoint(Δ)
         zerou = zero(sol.prob.u0)
         _Δ = @. ifelse(Δ === nothing, (zerou,), Δ)
-        nt = Zygote.nt_nothing(sol)
-        gs = Zygote.accum(nt, (u = _Δ,))
-        (gs,)
+        (build_solution(sol.prob, sol.alg, sol.t, _Δ),)
     end
     sol.u, solu_adjoint
 end

test/downstream/observables_autodiff.jl

@@ -3,6 +3,8 @@ using Zygote
 using ModelingToolkit: t_nounits as t, D_nounits as D
 import SymbolicIndexingInterface as SII
 import SciMLStructures as SS
+using ModelingToolkitStandardLibrary
+import ModelingToolkitStandardLibrary as MSL
 
 @parameters σ ρ β
 @variables x(t) y(t) z(t) w(t)
@@ -34,60 +36,18 @@ sol = solve(prob, Tsit5())
     du_ = [0.0, 1.0, 1.0, 1.0]
     du = [du_ for _ in sol.u]
     @test du == gs.u
-end
-
-# Lorenz
-
-@parameters σ ρ β
-@variables x(t) y(t) z(t)
-
-eqs = [D(x) ~ σ * (y - x),
-    D(y) ~ x * (ρ - z) - y,
-    D(z) ~ x * y - β * z]
-
-@named lorenz1 = ODESystem(eqs, t)
-@named lorenz2 = ODESystem(eqs, t)
-
-@parameters γ
-@variables a(t) α(t)
-connections = [0 ~ lorenz1.x + lorenz2.y + a * γ,
-    α ~ 2lorenz1.x + a * γ]
-@mtkbuild sys = ODESystem(connections, t, [a, α], [γ], systems = [lorenz1, lorenz2])
-
-u0 = [lorenz1.x => 1.0,
-    lorenz1.y => 0.0,
-    lorenz1.z => 0.0,
-    lorenz2.x => 0.0,
-    lorenz2.y => 1.0,
-    lorenz2.z => 0.0,
-    a => 2.0]
-
-p = [lorenz1.σ => 10.0,
-    lorenz1.ρ => 28.0,
-    lorenz1.β => 8 / 3,
-    lorenz2.σ => 10.0,
-    lorenz2.ρ => 28.0,
-    lorenz2.β => 8 / 3,
-    γ => 2.0]
-
-tspan = (0.0, 100.0)
-prob = ODEProblem(sys, u0, tspan, p)
-integ = init(prob, Rodas4())
-sol = solve(prob, Rodas4())
-
-gt = reduce(hcat, sol[[sys.a, sys.α]]) .+ randn.()
 
-gs, = Zygote.gradient(sol) do sol
-    mean(abs.(sol[[sys.a, sys.α]] .- gt), dims = 2)
+    # Observable in a vector
+    gs, = gradient(sol) do sol
+        sum(sum.(sol[[sys.w, sys.x]]))
+    end
+    du_ = [0.0, 1.0, 1.0, 2.0]
+    du = [du_ for _ in sol.u]
+    @test du == gs.u
 end
 
 # DAE
 
-using ModelingToolkit, OrdinaryDiffEq, Zygote
-using ModelingToolkitStandardLibrary
-import ModelingToolkitStandardLibrary as MSL
-using SciMLStructures
-
 function create_model(; C₁ = 3e-5, C₂ = 1e-6)
     @variables t
     @named resistor1 = MSL.Electrical.Resistor(R = 5.0)
@@ -112,15 +72,20 @@ function create_model(; C₁ = 3e-5, C₂ = 1e-6)
         ])
 end
 
-model = create_model()
-sys = structural_simplify(model)
+@testset "DAE Observable function AD" begin
+    model = create_model()
+    sys = structural_simplify(model)
+
+    prob = ODEProblem(sys, [], (0.0, 1.0))
+    sol = solve(prob, Rodas4())
 
-prob = ODEProblem(sys, [], (0.0, 1.0))
-sol = solve(prob, Rodas4())
-pf = getp(sol, sys.resistor1.R)
-mtkparams = SII.parameter_values(sol)
-tunables, _, _ = SS.canonicalize(SS.Tunable(), mtkparams)
-p_new = rand(length(tunables))
+    gs, = gradient(sol) do sol
+        sum(sol[sys.ampermeter.i])
+    end
+    du_ = [0.2, 1.0]
+    du = [du_ for _ in sol.u]
+    @test gs.u == du
+end
 
 # @testset "Adjoints with DAE" begin
 #     gs_mtkp, gs_p_new = gradient(mtkparams, p_new) do p, new_tunables