`sol[sym]` throws for observed expressions combining `@discretes` and continuous states

[martincornejo]

Here is a minimum example:

using ModelingToolkit
using ModelingToolkit: t_nounits as t, D_nounits as D
using OrdinaryDiffEq

@variables x(t) # continuous ODE state
@variables y(t) # observed: mixes discrete k and continuous x
@discretes k(t) # discrete parameter updated by callback


# Callback: double k every 1 second         
affect = ModelingToolkit.ImperativeAffect(modified=(; k)) do m, o, c, i
    (; k=m.k * 2.0)
end
cb = ModelingToolkit.SymbolicDiscreteCallback(1.0, affect)
eqs = [D(x) ~ -x,
    y ~ k * x,     # <-- mixes discrete k and continuous x                             
]
@mtkcompile sys = System(eqs, t; discrete_events=[cb])
prob = ODEProblem(sys, [sys.x => 1.0, sys.k => 1.0], (0.0, 3.0))
sol = solve(prob, Rodas5P(); saveat=0.1)

# This fails
sol[sys.y]

# This works:
sol(sol.t; idxs=sys.y).u

Expected: sol[sys.y] returns a vector of values at each saved timepoint, with k step-held between callback firings.

Error & Stacktrace ⚠️

Click to expand

ERROR:     Invalid indexing operation: tried to access object of type ODESolution{Float64, 2, Vector{Vector{Float64}}, Nothing, Nothing, Vector{Float64}, Vector{Vector{Vector{Float64}}}, SymbolicIndexingInterface.ParameterTimeseriesCollection{Tuple{RecursiveArrayTools.DiffEqArray{Any, 2, Vector{ModelingToolkitBase.NestedGetIndex{Tuple{Vector{Float64}}}}, Vector{Float64}, Nothing, Nothing, Nothing}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}}, ODEProblem{Vector{Float64}, Tuple{Float64, Float64}, true, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Base.Pairs{Symbol, CallbackSet{Tuple{}, Tuple{DiscreteCallback{DiffEqCallbacks.var"#88#89"{Bool, Float64, Base.RefValue{Int64}, Base.RefValue{Float64}}, DiffEqCallbacks.PeriodicCallbackAffect{ModelingToolkitBase.var"#406#407"{@NamedTuple{k::SymbolicIndexingInterface.ParameterHookWrapper{SymbolicIndexingInterface.SetParameterIndex{ModelingToolkitBase.ParameterIndex{SciMLStructures.Discrete, Tuple{Int64, Int64}}}, Num}}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0x5510a2c6, 0xf6484a63, 0xc0016c76, 0x6c375d78, 0x8c969ab1), Nothing}, Nothing}, Tuple{Symbol}, Tuple{}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0xfb11e620, 0xc3f23fe3, 0xf3f13c8f, 0xc8dfa2e3, 0x9a0f4072), Nothing}, Nothing}, var"#66#67", Nothing, Bool}, Float64, Base.RefValue{Float64}, Base.RefValue{Int64}}, DiffEqCallbacks.var"#90#91"{Int64, Bool, typeof(SciMLBase.INITIALIZE_DEFAULT), Float64, DiffEqCallbacks.PeriodicCallbackAffect{ModelingToolkitBase.var"#406#407"{@NamedTuple{k::SymbolicIndexingInterface.ParameterHookWrapper{SymbolicIndexingInterface.SetParameterIndex{ModelingToolkitBase.ParameterIndex{SciMLStructures.Discrete, Tuple{Int64, Int64}}}, Num}}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0x5510a2c6, 0xf6484a63, 0xc0016c76, 0x6c375d78, 0x8c969ab1), Nothing}, Nothing}, Tuple{Symbol}, Tuple{}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0xfb11e620, 0xc3f23fe3, 0xf3f13c8f, 0xc8dfa2e3, 0x9a0f4072), Nothing}, Nothing}, var"#66#67", Nothing, Bool}, Float64, Base.RefValue{Float64}, Base.RefValue{Int64}}, Base.RefValue{Int64}, Base.RefValue{Float64}}, typeof(SciMLBase.FINALIZE_DEFAULT), CheckInit, Vector{Int64}}}}, Nothing, @NamedTuple{callback::CallbackSet{Tuple{}, Tuple{DiscreteCallback{DiffEqCallbacks.var"#88#89"{Bool, Float64, Base.RefValue{Int64}, Base.RefValue{Float64}}, DiffEqCallbacks.PeriodicCallbackAffect{ModelingToolkitBase.var"#406#407"{@NamedTuple{k::SymbolicIndexingInterface.ParameterHookWrapper{SymbolicIndexingInterface.SetParameterIndex{ModelingToolkitBase.ParameterIndex{SciMLStructures.Discrete, Tuple{Int64, Int64}}}, Num}}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0x5510a2c6, 0xf6484a63, 0xc0016c76, 0x6c375d78, 0x8c969ab1), Nothing}, Nothing}, Tuple{Symbol}, Tuple{}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0xfb11e620, 0xc3f23fe3, 0xf3f13c8f, 0xc8dfa2e3, 0x9a0f4072), Nothing}, Nothing}, var"#66#67", Nothing, Bool}, Float64, Base.RefValue{Float64}, Base.RefValue{Int64}}, DiffEqCallbacks.var"#90#91"{Int64, Bool, typeof(SciMLBase.INITIALIZE_DEFAULT), Float64, DiffEqCallbacks.PeriodicCallbackAffect{ModelingToolkitBase.var"#406#407"{@NamedTuple{k::SymbolicIndexingInterface.ParameterHookWrapper{SymbolicIndexingInterface.SetParameterIndex{ModelingToolkitBase.ParameterIndex{SciMLStructures.Discrete, Tuple{Int64, Int64}}}, Num}}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0x5510a2c6, 0xf6484a63, 0xc0016c76, 0x6c375d78, 0x8c969ab1), Nothing}, Nothing}, Tuple{Symbol}, Tuple{}, ModelingToolkitBase.GeneratedFunctionWrapper{(2, 3, true), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :___mtkparameters___, :t), ModelingToolkitBase.var"#_RGF_ModTag", ModelingToolkitBase.var"#_RGF_ModTag", (0xfb11e620, 0xc3f23fe3, 0xf3f13c8f, 0xc8dfa2e3, 0x9a0f4072), Nothing}, Nothing}, var"#66#67", Nothing, Bool}, Float64, Base.RefValue{Float64}, Base.RefValue{Int64}}, Base.RefValue{Int64}, Base.RefValue{Float64}}, typeof(SciMLBase.FINALIZE_DEFAULT), CheckInit, Vector{Int64}}}}}}, SciMLBase.StandardODEProblem}, Rodas5P{1, ADTypes.AutoForwardDiff{1, ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}}, Nothing, typeof(OrdinaryDiffEqCore.DEFAULT_PRECS), Val{:forward}(), true, nothing, typeof(OrdinaryDiffEqCore.trivial_limiter!), typeof(OrdinaryDiffEqCore.trivial_limiter!)}, OrdinaryDiffEqCore.InterpolationData{ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Vector{Vector{Float64}}, Vector{Float64}, Vector{Vector{Vector{Float64}}}, Nothing, OrdinaryDiffEqRosenbrock.RosenbrockCache{Vector{Float64}, Vector{Float64}, Float64, Vector{Float64}, Matrix{Float64}, Matrix{Float64}, OrdinaryDiffEqRosenbrock.RodasTableau{Float64, Float64}, SciMLBase.TimeGradientWrapper{true, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}}, SciMLBase.UJacobianWrapper{true, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Float64, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}}, LinearSolve.LinearCache{Matrix{Float64}, Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, LinearSolve.DefaultLinearSolver, LinearSolve.DefaultLinearSolverInit{LU{Float64, Matrix{Float64}, Vector{Int64}}, LinearAlgebra.QRCompactWY{Float64, Matrix{Float64}, Matrix{Float64}}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Tuple{LU{Float64, Matrix{Float64}, Vector{Int64}}, Vector{Int64}}, Tuple{LU{Float64, Matrix{Float64}, Vector{Int64}}, Vector{Int64}}, Nothing, Nothing, Nothing, SVD{Float64, Float64, Matrix{Float64}, Vector{Float64}}, Cholesky{Float64, Matrix{Float64}}, Cholesky{Float64, Matrix{Float64}}, Tuple{LU{Float64, Matrix{Float64}, Vector{Int32}}, Base.RefValue{Int32}}, Tuple{LU{Float64, Matrix{Float64}, Vector{Int64}}, Base.RefValue{Int64}}, QRPivoted{Float64, Matrix{Float64}, Vector{Float64}, Vector{Int64}}, Nothing, Nothing, Nothing, Nothing, Nothing, Matrix{Float64}, Vector{Float64}}, LinearSolve.InvPreconditioner{Diagonal{Float64, Vector{Float64}}}, Diagonal{Float64, Vector{Float64}}, Float64, LinearSolve.LinearVerbosity{SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.WarnLevel, SciMLLogging.WarnLevel, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent, SciMLLogging.Silent}, Bool, LinearSolve.LinearSolveAdjoint{Missing}}, Tuple{DifferentiationInterfaceForwardDiffExt.ForwardDiffTwoArgJacobianPrep{Nothing, ForwardDiff.JacobianConfig{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, Tuple{}}, DifferentiationInterfaceForwardDiffExt.ForwardDiffTwoArgJacobianPrep{Nothing, ForwardDiff.JacobianConfig{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, Tuple{}}}, Tuple{DifferentiationInterfaceForwardDiffExt.ForwardDiffTwoArgDerivativePrep{Tuple{SciMLBase.TimeGradientWrapper{true, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}}, Vector{Float64}, ADTypes.AutoForwardDiff{1, ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}}, Float64, Tuple{}}, Float64, ForwardDiff.DerivativeConfig{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, Tuple{}}, DifferentiationInterfaceForwardDiffExt.ForwardDiffTwoArgDerivativePrep{Tuple{SciMLBase.TimeGradientWrapper{true, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, Float64}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkitBase.ObservedFunctionCache{System, Nothing}, Nothing, System, Union{Nothing, SciMLBase.OverrideInitData}, Union{Nothing, SciMLBase.ODENLStepData}}, Vector{Float64}, MTKParameters{StaticArraysCore.SVector{0, Float64}, Vector{Float64}, Tuple{BlockArrays.BlockedVector{Float64, Vector{Float64}, Tuple{BlockArrays.BlockedOneTo{Int64, Vector{Int64}}}}}, Tuple{}, Tuple{}, Tuple{}}}, Vector{Float64}, ADTypes.AutoForwardDiff{1, ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}}, Float64, Tuple{}}, Float64, ForwardDiff.DerivativeConfig{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, Tuple{}}}, Float64, Rodas5P{1, ADTypes.AutoForwardDiff{1, ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}}, Nothing, typeof(OrdinaryDiffEqCore.DEFAULT_PRECS), Val{:forward}(), true, nothing, typeof(OrdinaryDiffEqCore.trivial_limiter!), typeof(OrdinaryDiffEqCore.trivial_limiter!)}, typeof(OrdinaryDiffEqCore.trivial_limiter!), typeof(OrdinaryDiffEqCore.trivial_limiter!)}, Nothing}, SciMLBase.DEStats, Nothing, Nothing, Nothing, Nothing} (which is a parameter timeseries object) with variables having mixed timeseries indexes Any[SymbolicIndexingInterface.ContinuousTimeseries(), 1].

Stacktrace:
 [1] (::SymbolicIndexingInterface.TimeDependentObservedFunction{…})(::SymbolicIndexingInterface.Timeseries, ::SymbolicIndexingInterface.IndexerMixedTimeseries, ::ODESolution{…})
   @ SymbolicIndexingInterface C:\Users\wsworker\.julia\packages\SymbolicIndexingInterface\D9aQf\src\state_indexing.jl:125
 [2] (::SymbolicIndexingInterface.TimeDependentObservedFunction{…})(::SymbolicIndexingInterface.Timeseries, ::ODESolution{…})
   @ SymbolicIndexingInterface C:\Users\wsworker\.julia\packages\SymbolicIndexingInterface\D9aQf\src\state_indexing.jl:80
 [3] (::SymbolicIndexingInterface.TimeDependentObservedFunction{…})(prob::ODESolution{…})
   @ SymbolicIndexingInterface C:\Users\wsworker\.julia\packages\SymbolicIndexingInterface\D9aQf\src\value_provider_interface.jl:166
 [4] _getindex
   @ C:\Users\wsworker\.julia\packages\RecursiveArrayTools\AvG3i\src\vector_of_array.jl:694 [inlined]
 [5] getindex(::ODESolution{…}, ::Num)
   @ RecursiveArrayTools C:\Users\wsworker\.julia\packages\RecursiveArrayTools\AvG3i\src\vector_of_array.jl:1011
 [6] top-level scope
   @ d:\Austausch\MC\stabl-digital-twin\mwe.jl:23
Some type information was truncated. Use `show(err)` to see complete types.

Environment (please complete the following information):

• Output of using Pkg; Pkg.status()

(DigitalTwinBatteryMMC) pkg> st
Project DigitalTwinBatteryMMC v0.1.0
Status `D:\Austausch\MC\stabl-digital-twin\Project.toml`
  [6e4b80f9] BenchmarkTools v1.6.3
  [336ed68f] CSV v0.10.16
  [13f3f980] CairoMakie v0.15.9
  [a93c6f00] DataFrames v1.8.1
  [82cc6244] DataInterpolations v8.9.0
  [459566f4] DiffEqCallbacks v4.12.0
  [e9467ef8] GLMakie v0.13.9
  [d8418881] Intervals v1.11.0
  [961ee093] ModelingToolkit v11.14.0
  [16a59e39] ModelingToolkitStandardLibrary v2.27.0
  [8913a72c] NonlinearSolve v4.16.0
  [1dea7af3] OrdinaryDiffEq v6.108.0
  [6099a3de] PythonCall v0.9.31
  [7b8617ff] QuackIO v0.1.5
  [0bca4576] SciMLBase v2.148.0
  [37e2e46d] LinearAlgebra v1.12.0

• Output of using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)

Click to expand

(DigitalTwinBatteryMMC) pkg> st -m
Project DigitalTwinBatteryMMC v0.1.0
Status `D:\Austausch\MC\stabl-digital-twin\Manifest.toml`
  [47edcb42] ADTypes v1.21.0
  [621f4979] AbstractFFTs v1.5.0
  [6e696c72] AbstractPlutoDingetjes v1.3.2
  [1520ce14] AbstractTrees v0.4.5
  [7d9f7c33] Accessors v0.1.43
  [79e6a3ab] Adapt v4.5.0
  [35492f91] AdaptivePredicates v1.2.0
  [66dad0bd] AliasTables v1.1.3
  [27a7e980] Animations v0.4.2
  [ec485272] ArnoldiMethod v0.4.0
  [4fba245c] ArrayInterface v7.23.0
  [4c555306] ArrayLayouts v1.12.2
  [31f734f8] ArrowTypes v2.3.0
  [67c07d97] Automa v1.1.0
  [13072b0f] AxisAlgorithms v1.1.0
  [39de3d68] AxisArrays v0.4.8
  [18cc8868] BaseDirs v1.3.2
  [6e4b80f9] BenchmarkTools v1.6.3
  [e2ed5e7c] Bijections v0.2.2
  [caf10ac8] BipartiteGraphs v0.1.7
  [c3b6d118] BitIntegers v0.3.7
  [62783981] BitTwiddlingConvenienceFunctions v0.1.6
  [8e7c35d0] BlockArrays v1.9.3
  [70df07ce] BracketingNonlinearSolve v1.11.0
  [fa961155] CEnum v0.5.0
  [2a0fbf3d] CPUSummary v0.2.7
  [96374032] CRlibm v1.0.2
  [336ed68f] CSV v0.10.16
  [159f3aea] Cairo v1.1.1
  [13f3f980] CairoMakie v0.15.9
  [d360d2e6] ChainRulesCore v1.26.0
  [fb6a15b2] CloseOpenIntervals v0.1.13
  [944b1d66] CodecZlib v0.7.8
  [a2cac450] ColorBrewer v0.4.2
  [35d6a980] ColorSchemes v3.31.0
  [3da002f7] ColorTypes v0.12.1
  [c3611d14] ColorVectorSpace v0.11.0
  [5ae59095] Colors v0.13.1
⌅ [861a8166] Combinatorics v1.0.2
  [38540f10] CommonSolve v0.2.6
  [bbf7d656] CommonSubexpressions v0.3.1
  [f70d9fcc] CommonWorldInvalidations v1.0.0
  [34da2185] Compat v4.18.1
  [b152e2b5] CompositeTypes v0.1.4
  [a33af91c] CompositionsBase v0.1.2
  [95dc2771] ComputePipeline v0.1.7
  [2569d6c7] ConcreteStructs v0.2.3
  [992eb4ea] CondaPkg v0.2.34
  [187b0558] ConstructionBase v1.6.0
  [d38c429a] Contour v0.6.3
  [adafc99b] CpuId v0.3.1
  [a8cc5b0e] Crayons v4.1.1
  [a10d1c49] DBInterface v2.6.1
  [9a962f9c] DataAPI v1.16.0
  [a93c6f00] DataFrames v1.8.1
  [82cc6244] DataInterpolations v8.9.0
  [864edb3b] DataStructures v0.19.3
  [e2d170a0] DataValueInterfaces v1.0.0
  [927a84f5] DelaunayTriangulation v1.6.6
  [2b5f629d] DiffEqBase v6.210.1
  [459566f4] DiffEqCallbacks v4.12.0
  [163ba53b] DiffResults v1.1.0
  [b552c78f] DiffRules v1.15.1
  [a0c0ee7d] DifferentiationInterface v0.7.16
  [31c24e10] Distributions v0.25.123
  [ffbed154] DocStringExtensions v0.9.5
  [5b8099bc] DomainSets v0.7.16
  [d2f5444f] DuckDB v1.4.1
  [7c1d4256] DynamicPolynomials v0.6.4
  [4e289a0a] EnumX v1.0.7
  [f151be2c] EnzymeCore v0.8.18
  [429591f6] ExactPredicates v2.2.9
  [d4d017d3] ExponentialUtilities v1.30.0
  [e2ba6199] ExprTools v0.1.10
  [55351af7] ExproniconLite v0.10.14
  [411431e0] Extents v0.1.6
  [b86e33f2] FFTA v0.3.1
  [7034ab61] FastBroadcast v0.3.5
  [9aa1b823] FastClosures v0.3.2
  [442a2c76] FastGaussQuadrature v1.1.0
  [a4df4552] FastPower v1.3.1
  [5789e2e9] FileIO v1.18.0
  [8fc22ac5] FilePaths v0.9.0
  [48062228] FilePathsBase v0.9.24
  [1a297f60] FillArrays v1.16.0
  [64ca27bc] FindFirstFunctions v1.8.0
  [6a86dc24] FiniteDiff v2.29.0
  [fb4d412d] FixedPointDecimals v0.6.4
  [53c48c17] FixedPointNumbers v0.8.5
  [1fa38f19] Format v1.3.7
  [f6369f11] ForwardDiff v1.3.2
  [b38be410] FreeType v4.1.1
  [663a7486] FreeTypeAbstraction v0.10.8
  [069b7b12] FunctionWrappers v1.1.3
  [77dc65aa] FunctionWrappersWrappers v0.1.3
  [f7f18e0c] GLFW v3.4.6
  [e9467ef8] GLMakie v0.13.9
  [46192b85] GPUArraysCore v0.2.0
  [c145ed77] GenericSchur v0.5.6
  [5c1252a2] GeometryBasics v0.5.10
  [a2bd30eb] Graphics v1.1.3
  [86223c79] Graphs v1.14.0
  [3955a311] GridLayoutBase v0.11.2
  [42e2da0e] Grisu v1.0.2
  [34004b35] HypergeometricFunctions v0.3.28
  [615f187c] IfElse v0.1.1
  [2803e5a7] ImageAxes v0.6.12
  [c817782e] ImageBase v0.1.7
  [a09fc81d] ImageCore v0.10.5
  [82e4d734] ImageIO v0.6.9
  [bc367c6b] ImageMetadata v0.9.10
  [3263718b] ImplicitDiscreteSolve v1.8.0
  [9b13fd28] IndirectArrays v1.0.0
  [d25df0c9] Inflate v0.1.5
  [842dd82b] InlineStrings v1.4.5
  [18e54dd8] IntegerMathUtils v0.1.3
  [a98d9a8b] Interpolations v0.16.2
  [d1acc4aa] IntervalArithmetic v1.0.2
  [8197267c] IntervalSets v0.7.13
  [d8418881] Intervals v1.11.0
  [3587e190] InverseFunctions v0.1.17
  [41ab1584] InvertedIndices v1.3.1
  [92d709cd] IrrationalConstants v0.2.6
  [f1662d9f] Isoband v0.1.1
  [c8e1da08] IterTools v1.10.0
  [82899510] IteratorInterfaceExtensions v1.0.0
  [692b3bcd] JLLWrappers v1.7.1
  [682c06a0] JSON v1.4.0
  [ae98c720] Jieko v0.2.1
  [b835a17e] JpegTurbo v0.1.6
  [ccbc3e58] JumpProcesses v9.23.1
  [5ab0869b] KernelDensity v0.6.11
  [ba0b0d4f] Krylov v0.10.6
  [b964fa9f] LaTeXStrings v1.4.0
  [10f19ff3] LayoutPointers v0.1.17
  [8cdb02fc] LazyModules v0.3.1
  [87fe0de2] LineSearch v0.1.6
  [d3d80556] LineSearches v7.6.0
  [7ed4a6bd] LinearSolve v3.64.0
  [2ab3a3ac] LogExpFunctions v0.3.29
  [e6f89c97] LoggingExtras v1.2.0
  [1914dd2f] MacroTools v0.5.16
  [ee78f7c6] Makie v0.24.9
  [d125e4d3] ManualMemory v0.1.8
  [dbb5928d] MappedArrays v0.4.3
  [0a4f8689] MathTeXEngine v0.6.7
  [bb5d69b7] MaybeInplace v0.1.4
  [7269a6da] MeshIO v0.5.3
  [0b3b1443] MicroMamba v0.1.15
  [e1d29d7a] Missings v1.2.0
  [78c3b35d] Mocking v0.8.1
  [961ee093] ModelingToolkit v11.14.0
  [7771a370] ModelingToolkitBase v1.21.0
  [16a59e39] ModelingToolkitStandardLibrary v2.27.0
  [6bb917b9] ModelingToolkitTearing v1.6.0
  [66fc600b] ModernGL v1.1.8
  [e94cdb99] MosaicViews v0.3.4
  [2e0e35c7] Moshi v0.3.7
  [46d2c3a1] MuladdMacro v0.2.4
  [102ac46a] MultivariatePolynomials v0.5.13
  [d8a4904e] MutableArithmetics v1.6.7
  [d41bc354] NLSolversBase v8.0.0
  [77ba4419] NaNMath v1.1.3
  [f09324ee] Netpbm v1.1.1
  [8913a72c] NonlinearSolve v4.16.0
  [be0214bd] NonlinearSolveBase v2.15.0
  [5959db7a] NonlinearSolveFirstOrder v2.0.0
  [9a2c21bd] NonlinearSolveQuasiNewton v1.12.0
  [26075421] NonlinearSolveSpectralMethods v1.6.0
  [510215fc] Observables v0.5.5
  [6fe1bfb0] OffsetArrays v1.17.0
  [52e1d378] OpenEXR v0.3.3
  [bac558e1] OrderedCollections v1.8.1
  [1dea7af3] OrdinaryDiffEq v6.108.0
  [89bda076] OrdinaryDiffEqAdamsBashforthMoulton v1.9.0
  [6ad6398a] OrdinaryDiffEqBDF v1.22.0
  [bbf590c4] OrdinaryDiffEqCore v3.17.0
  [50262376] OrdinaryDiffEqDefault v1.13.0
  [4302a76b] OrdinaryDiffEqDifferentiation v2.2.1
  [9286f039] OrdinaryDiffEqExplicitRK v1.9.0
  [e0540318] OrdinaryDiffEqExponentialRK v1.13.0
  [becaefa8] OrdinaryDiffEqExtrapolation v1.16.0
  [5960d6e9] OrdinaryDiffEqFIRK v1.23.0
  [101fe9f7] OrdinaryDiffEqFeagin v1.8.0
  [d3585ca7] OrdinaryDiffEqFunctionMap v1.9.0
  [d28bc4f8] OrdinaryDiffEqHighOrderRK v1.9.0
  [9f002381] OrdinaryDiffEqIMEXMultistep v1.12.0
  [521117fe] OrdinaryDiffEqLinear v1.10.0
  [1344f307] OrdinaryDiffEqLowOrderRK v1.10.0
  [b0944070] OrdinaryDiffEqLowStorageRK v1.12.0
  [127b3ac7] OrdinaryDiffEqNonlinearSolve v1.23.0
  [c9986a66] OrdinaryDiffEqNordsieck v1.9.0
  [5dd0a6cf] OrdinaryDiffEqPDIRK v1.11.0
  [5b33eab2] OrdinaryDiffEqPRK v1.8.0
  [04162be5] OrdinaryDiffEqQPRK v1.8.0
  [af6ede74] OrdinaryDiffEqRKN v1.10.0
  [43230ef6] OrdinaryDiffEqRosenbrock v1.25.0
  [2d112036] OrdinaryDiffEqSDIRK v1.12.0
  [669c94d9] OrdinaryDiffEqSSPRK v1.11.0
  [e3e12d00] OrdinaryDiffEqStabilizedIRK v1.11.0
  [358294b1] OrdinaryDiffEqStabilizedRK v1.8.0
  [fa646aed] OrdinaryDiffEqSymplecticRK v1.11.0
  [b1df2697] OrdinaryDiffEqTsit5 v1.9.0
  [79d7bb75] OrdinaryDiffEqVerner v1.11.0
  [90014a1f] PDMats v0.11.37
  [f57f5aa1] PNGFiles v0.4.4
  [19eb6ba3] Packing v0.5.1
  [5432bcbf] PaddedViews v0.5.12
  [69de0a69] Parsers v2.8.3
  [fa939f87] Pidfile v1.3.0
  [eebad327] PkgVersion v0.3.3
  [995b91a9] PlotUtils v1.4.4
  [e409e4f3] PoissonRandom v0.4.7
  [f517fe37] Polyester v0.7.19
  [1d0040c9] PolyesterWeave v0.2.2
  [647866c9] PolygonOps v0.1.2
  [2dfb63ee] PooledArrays v1.4.3
  [d236fae5] PreallocationTools v1.1.2
  [aea7be01] PrecompileTools v1.3.3
  [21216c6a] Preferences v1.5.2
  [08abe8d2] PrettyTables v3.2.3
  [27ebfcd6] Primes v0.5.7
  [92933f4c] ProgressMeter v1.11.0
  [43287f4e] PtrArrays v1.4.0
  [6099a3de] PythonCall v0.9.31
  [4b34888f] QOI v1.0.2
  [7b8617ff] QuackIO v0.1.5
  [1fd47b50] QuadGK v2.11.2
  [b3c3ace0] RangeArrays v0.3.2
  [c84ed2f1] Ratios v0.4.5
  [988b38a3] ReadOnlyArrays v0.2.0
  [795d4caa] ReadOnlyDicts v1.0.1
  [3cdcf5f2] RecipesBase v1.3.4
  [731186ca] RecursiveArrayTools v3.48.0
  [189a3867] Reexport v1.2.2
  [05181044] RelocatableFolders v1.0.1
  [ae029012] Requires v1.3.1
  [79098fc4] Rmath v0.9.0
  [5eaf0fd0] RoundingEmulator v0.2.1
  [7e49a35a] RuntimeGeneratedFunctions v0.5.17
  [9dfe8606] SCCNonlinearSolve v1.11.0
  [fdea26ae] SIMD v3.7.2
  [94e857df] SIMDTypes v0.1.0
  [0bca4576] SciMLBase v2.148.0
  [19f34311] SciMLJacobianOperators v0.1.12
  [a6db7da4] SciMLLogging v1.9.1
  [c0aeaf25] SciMLOperators v1.15.1
  [431bcebd] SciMLPublic v1.0.1
  [53ae85a6] SciMLStructures v1.10.0
  [6c6a2e73] Scratch v1.3.0
  [91c51154] SentinelArrays v1.4.9
  [efcf1570] Setfield v1.1.2
  [65257c39] ShaderAbstractions v0.5.0
  [992d4aef] Showoff v1.0.3
  [73760f76] SignedDistanceFields v0.4.1
  [727e6d20] SimpleNonlinearSolve v2.11.0
  [699a6c99] SimpleTraits v0.9.5
  [45858cf5] Sixel v0.1.5
  [a2af1166] SortingAlgorithms v1.2.2
  [0a514795] SparseMatrixColorings v0.4.24
  [276daf66] SpecialFunctions v2.7.1
  [860ef19b] StableRNGs v1.0.4
  [cae243ae] StackViews v0.1.2
  [64909d44] StateSelection v1.4.0
  [aedffcd0] Static v1.3.1
  [0d7ed370] StaticArrayInterface v1.9.0
  [90137ffa] StaticArrays v1.9.17
  [1e83bf80] StaticArraysCore v1.4.4
  [10745b16] Statistics v1.11.1
  [82ae8749] StatsAPI v1.8.0
  [2913bbd2] StatsBase v0.34.10
  [4c63d2b9] StatsFuns v1.5.2
  [7792a7ef] StrideArraysCore v0.5.8
  [892a3eda] StringManipulation v0.4.4
  [09ab397b] StructArrays v0.7.2
  [ec057cc2] StructUtils v2.6.3
  [2efcf032] SymbolicIndexingInterface v0.3.46
  [19f23fe9] SymbolicLimits v1.1.0
  [d1185830] SymbolicUtils v4.19.0
  [0c5d862f] Symbolics v7.15.3
  [dc5dba14] TZJData v1.5.0+2025b
  [3783bdb8] TableTraits v1.0.1
  [bd369af6] Tables v1.12.1
  [ed4db957] TaskLocalValues v0.1.3
  [62fd8b95] TensorCore v0.1.1
  [8ea1fca8] TermInterface v2.0.0
  [8290d209] ThreadingUtilities v0.5.5
  [731e570b] TiffImages v0.11.8
  [f269a46b] TimeZones v1.22.2
  [a759f4b9] TimerOutputs v0.5.29
  [3bb67fe8] TranscodingStreams v0.11.3
  [981d1d27] TriplotBase v0.1.0
  [781d530d] TruncatedStacktraces v1.4.0
  [3a884ed6] UnPack v1.0.2
  [1cfade01] UnicodeFun v0.4.1
  [1986cc42] Unitful v1.28.0
  [e17b2a0c] UnsafePointers v1.0.0
  [d30d5f5c] WeakCacheSets v0.1.0
  [ea10d353] WeakRefStrings v1.4.2
  [e3aaa7dc] WebP v0.1.3
  [efce3f68] WoodburyMatrices v1.1.0
  [76eceee3] WorkerUtilities v1.6.1
  [6e34b625] Bzip2_jll v1.0.9+0
  [4e9b3aee] CRlibm_jll v1.0.1+0
  [83423d85] Cairo_jll v1.18.5+1
  [ee1fde0b] Dbus_jll v1.16.2+0
  [2cbbab25] DuckDB_jll v1.4.4+0
  [5ae413db] EarCut_jll v2.2.4+0
  [2702e6a9] EpollShim_jll v0.0.20230411+1
  [2e619515] Expat_jll v2.7.3+0
  [b22a6f82] FFMPEG_jll v8.0.1+0
  [a3f928ae] Fontconfig_jll v2.17.1+0
  [d7e528f0] FreeType2_jll v2.13.4+0
  [559328eb] FriBidi_jll v1.0.17+0
  [0656b61e] GLFW_jll v3.4.1+0
  [b0724c58] GettextRuntime_jll v0.22.4+0
  [59f7168a] Giflib_jll v5.2.3+0
  [7746bdde] Glib_jll v2.86.3+0
  [3b182d85] Graphite2_jll v1.3.15+0
  [2e76f6c2] HarfBuzz_jll v8.5.1+0
  [905a6f67] Imath_jll v3.2.2+0
  [1d5cc7b8] IntelOpenMP_jll v2025.2.0+0
  [aacddb02] JpegTurbo_jll v3.1.4+0
  [c1c5ebd0] LAME_jll v3.100.3+0
  [88015f11] LERC_jll v4.0.1+0
  [1d63c593] LLVMOpenMP_jll v18.1.8+0
  [dd4b983a] LZO_jll v2.10.3+0
⌅ [e9f186c6] Libffi_jll v3.4.7+0
  [7e76a0d4] Libglvnd_jll v1.7.1+1
  [94ce4f54] Libiconv_jll v1.18.0+0
  [4b2f31a3] Libmount_jll v2.41.3+0
  [89763e89] Libtiff_jll v4.7.2+0
  [38a345b3] Libuuid_jll v2.41.3+0
  [856f044c] MKL_jll v2025.2.0+0
  [e7412a2a] Ogg_jll v1.3.6+0
  [6cdc7f73] OpenBLASConsistentFPCSR_jll v0.3.30+0
  [18a262bb] OpenEXR_jll v3.4.4+0
  [efe28fd5] OpenSpecFun_jll v0.5.6+0
  [91d4177d] Opus_jll v1.6.1+0
  [36c8627f] Pango_jll v1.57.0+0
⌅ [30392449] Pixman_jll v0.44.2+0
  [f50d1b31] Rmath_jll v0.5.1+0
  [a2964d1f] Wayland_jll v1.24.0+0
  [ffd25f8a] XZ_jll v5.8.2+0
  [4f6342f7] Xorg_libX11_jll v1.8.13+0
  [0c0b7dd1] Xorg_libXau_jll v1.0.13+0
  [935fb764] Xorg_libXcursor_jll v1.2.4+0
  [a3789734] Xorg_libXdmcp_jll v1.1.6+0
  [1082639a] Xorg_libXext_jll v1.3.8+0
  [d091e8ba] Xorg_libXfixes_jll v6.0.2+0
  [a51aa0fd] Xorg_libXi_jll v1.8.3+0
  [d1454406] Xorg_libXinerama_jll v1.1.7+0
  [ec84b674] Xorg_libXrandr_jll v1.5.6+0
  [ea2f1a96] Xorg_libXrender_jll v0.9.12+0
  [c7cfdc94] Xorg_libxcb_jll v1.17.1+0
  [cc61e674] Xorg_libxkbfile_jll v1.2.0+0
  [35661453] Xorg_xkbcomp_jll v1.4.7+0
  [33bec58e] Xorg_xkeyboard_config_jll v2.44.0+0
  [c5fb5394] Xorg_xtrans_jll v1.6.0+0
  [3161d3a3] Zstd_jll v1.5.7+1
  [9a68df92] isoband_jll v0.2.3+0
  [a4ae2306] libaom_jll v3.13.1+0
  [0ac62f75] libass_jll v0.17.4+0
  [1183f4f0] libdecor_jll v0.2.2+0
  [f638f0a6] libfdk_aac_jll v2.0.4+0
  [b53b4c65] libpng_jll v1.6.55+0
  [075b6546] libsixel_jll v1.10.5+0
  [f27f6e37] libvorbis_jll v1.3.8+0
  [c5f90fcd] libwebp_jll v1.6.0+0
  [f8abcde7] micromamba_jll v2.3.1+0
  [1317d2d5] oneTBB_jll v2022.0.0+1
  [4d7b5844] pixi_jll v0.41.3+0
⌅ [1270edf5] x264_jll v10164.0.1+0
  [dfaa095f] x265_jll v4.1.0+0
  [d8fb68d0] xkbcommon_jll v1.13.0+0
  [0dad84c5] ArgTools v1.1.2
  [56f22d72] Artifacts v1.11.0
  [2a0f44e3] Base64 v1.11.0
  [8bf52ea8] CRC32c v1.11.0
  [ade2ca70] Dates v1.11.0
  [8ba89e20] Distributed v1.11.0
  [f43a241f] Downloads v1.7.0
  [7b1f6079] FileWatching v1.11.0
  [9fa8497b] Future v1.11.0
  [b77e0a4c] InteractiveUtils v1.11.0
  [ac6e5ff7] JuliaSyntaxHighlighting v1.12.0
  [4af54fe1] LazyArtifacts v1.11.0
  [b27032c2] LibCURL v0.6.4
  [76f85450] LibGit2 v1.11.0
  [8f399da3] Libdl v1.11.0
  [37e2e46d] LinearAlgebra v1.12.0
  [56ddb016] Logging v1.11.0
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  [2f01184e] SparseArrays v1.12.0
  [f489334b] StyledStrings v1.11.0
  [4607b0f0] SuiteSparse
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  [4ec0a83e] Unicode v1.11.0
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  [29816b5a] LibSSH2_jll v1.11.3+1
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  [3f19e933] p7zip_jll v17.7.0+0
Info Packages marked with ⌅ have new versions available but compatibility constraints restrict them from upgrading. To see why use `status --outdated -m`

• Output of versioninfo()

julia> versioninfo()
Julia Version 1.12.5
Commit 5fe89b8ddc (2026-02-09 16:05 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 24 × Intel(R) Xeon(R) W-2265 CPU @ 3.50GHz
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, cascadelake)
  GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 24 virtual cores)
Environment:
  JULIA_EDITOR = code
  JULIA_VSCODE_REPL = 1

[AayushSabharwal]

This is a known limitation of SymbolicIndexingInterface, and by extension ModelingToolkit. The symbolic indexing infrastructure only recognizes two types of variabilities:

• continuous variables, which have values at every time point saved in the solution and can be interpolated to any point in between
• clocked variables, which only exist at the specific time points when the clock ticks (callback triggers). Accessing these variables at any other time point is then invalid.

This means that continuous and clocked variables cannot be mixed. Unfortunately, there is a third type of variability - piecewise constant. These variables change their values at a countable number of points and hold constant in between. Semantically, they can be accessed identically to continuous variables. The symbolic indexing infrastructure does not allow for this behavior.

[ChrisRackauckas]

But you can use Hold variables?

[AayushSabharwal]

Not really. Interpolation allows accessing arbitrary variables at arbitrary time points, but not indexing.

[AayushSabharwal]

Hold is effectively the third type of variability. There is no API to tell SII "this expression requires these discrete variables to be updated" without also implying that the expression is clocked. This then runs into the error which prevents mixing clocks.

[ChrisRackauckas]

But you can hold variables to make them continuous and then interpolate. That should be sufficient for what is attempted in this actual issue?

[AayushSabharwal]

Interpolation doesn't require the Hold, just interpolation with the expression will suffice.

[martincornejo]

Notice that the following works:

sol(sol.t; idxs=sys.y).u

So I was confused that this didn't

sol[sys.y]

Is it not the same, but with different syntax? Or what is the difference?

[AayushSabharwal]

They are different. sol[sym] for continuous sym returns the values at the time points where the solution is saved. The sol(..) API allows querying the solution at arbitrary points (not necessarily the ones in sol.t).