Erroe when plotting observed variable(s)

[sosiristseng]

Describe the bug 🐞

When plotting observed variables, there is a TypoError thrown. (ERROR: TypeError: non-boolean (SymbolicUtils.BasicSymbolic{Bool}) used in boolean context)

Expected behavior

It should plot the time-series of observed variables.

Minimal Reproducible Example 👇

https://docs.sciml.ai/ModelingToolkit/dev/tutorials/ode_modeling/#Algebraic-relations-and-structural-simplification

using ModelingToolkit
using DifferentialEquations
using Plots

@variables t

@mtkmodel FOL begin
    @parameters begin
        τ # parameters
    end
    @variables begin
        x(t) # dependent variables
        RHS(t)
    end
    begin
        D = Differential(t)
    end
    @equations begin
        RHS ~ (1 - x) / τ
        D(x) ~ RHS
    end
end

@mtkbuild fol = FOL()

observed(fol)

prob = ODEProblem(fol,
    [fol.x => 0.0],
    (0.0, 10.0),
    [fol.τ => 3.0])

sol = solve(prob)
plot(sol, idxs = [fol.x, fol.RHS]) # Error here

Error & Stacktrace ⚠️

ERROR: TypeError: non-boolean (SymbolicUtils.BasicSymbolic{Bool}) used in boolean context
Stacktrace:
 [1] interpret_vars(vars::Vector{…}, sol::ODESolution{…}, syms::Vector{…})
   @ SciMLBase C:\Users\sosiristseng\.julia\packages\SciMLBase\FO0Bd\src\solutions\solution_interface.jl:399
 [2] macro expansion
   @ C:\Users\sosiristseng\.julia\packages\SciMLBase\FO0Bd\src\solutions\solution_interface.jl:180 [inlined]
 [3] apply_recipe(plotattributes::AbstractDict{Symbol, Any}, sol::SciMLBase.AbstractTimeseriesSolution)     
   @ SciMLBase C:\Users\sosiristseng\.julia\packages\RecipesBase\BRe07\src\RecipesBase.jl:300
 [4] _process_userrecipes!(plt::Any, plotattributes::Any, args::Any)
   @ RecipesPipeline C:\Users\sosiristseng\.julia\packages\RecipesPipeline\BGM3l\src\user_recipe.jl:38
 [5] recipe_pipeline!(plt::Any, plotattributes::Any, args::Any)
   @ RecipesPipeline C:\Users\sosiristseng\.julia\packages\RecipesPipeline\BGM3l\src\RecipesPipeline.jl:72
 [6] _plot!(plt::Plots.Plot, plotattributes::Any, args::Any)
   @ Plots C:\Users\sosiristseng\.julia\packages\Plots\sxUvK\src\plot.jl:223
 [7] plot(args::Any; kw...)
   @ Plots C:\Users\sosiristseng\.julia\packages\Plots\sxUvK\src\plot.jl:102
 [8] top-level scope
   @ c:\Users\sosiristseng\github\mkt-test\test.jl:34
Some type information was truncated. Use `show(err)` to see complete types.

Environment (please complete the following information):

• Output of using Pkg; Pkg.status()

Status `C:\Users\sosiristseng\github\mkt-test\Project.toml`
  [0c46a032] DifferentialEquations v7.12.0
  [961ee093] ModelingToolkit v8.74.1
  [91a5bcdd] Plots v1.39.0

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

Click me

Status `C:\Users\sosiristseng\github\mkt-test\Manifest.toml`
  [47edcb42] ADTypes v0.2.6
  [c3fe647b] AbstractAlgebra v0.34.7
  [1520ce14] AbstractTrees v0.4.4
⌅ [79e6a3ab] Adapt v3.7.2
  [ec485272] ArnoldiMethod v0.2.0
  [4fba245c] ArrayInterface v7.7.0
  [4c555306] ArrayLayouts v1.4.5
  [aae01518] BandedMatrices v1.4.0
  [e2ed5e7c] Bijections v0.1.6
  [d1d4a3ce] BitFlags v0.1.8
  [62783981] BitTwiddlingConvenienceFunctions v0.1.5
⌃ [764a87c0] BoundaryValueDiffEq v5.6.0
  [fa961155] CEnum v0.5.0
  [2a0fbf3d] CPUSummary v0.2.4
  [00ebfdb7] CSTParser v3.3.6
  [49dc2e85] Calculus v0.5.1
  [d360d2e6] ChainRulesCore v1.19.0
  [fb6a15b2] CloseOpenIntervals v0.1.12
  [944b1d66] CodecZlib v0.7.3
  [35d6a980] ColorSchemes v3.24.0
  [3da002f7] ColorTypes v0.11.4
  [c3611d14] ColorVectorSpace v0.10.0
  [5ae59095] Colors v0.12.10
  [861a8166] Combinatorics v1.0.2
  [a80b9123] CommonMark v0.8.12
  [38540f10] CommonSolve v0.2.4
  [bbf7d656] CommonSubexpressions v0.3.0
  [34da2185] Compat v4.10.1
  [b152e2b5] CompositeTypes v0.1.3
  [2569d6c7] ConcreteStructs v0.2.3
  [f0e56b4a] ConcurrentUtilities v2.3.0
  [187b0558] ConstructionBase v1.5.4
  [d38c429a] Contour v0.6.2
  [adafc99b] CpuId v0.3.1
  [a8cc5b0e] Crayons v4.1.1
  [9a962f9c] DataAPI v1.15.0
  [864edb3b] DataStructures v0.18.15
  [e2d170a0] DataValueInterfaces v1.0.0
  [bcd4f6db] DelayDiffEq v5.45.0
  [8bb1440f] DelimitedFiles v1.9.1
  [2b5f629d] DiffEqBase v6.145.0
  [459566f4] DiffEqCallbacks v2.36.1
  [77a26b50] DiffEqNoiseProcess v5.20.0
  [163ba53b] DiffResults v1.1.0
  [b552c78f] DiffRules v1.15.1
  [0c46a032] DifferentialEquations v7.12.0
  [b4f34e82] Distances v0.10.11
  [31c24e10] Distributions v0.25.104
  [ffbed154] DocStringExtensions v0.9.3
⌅ [5b8099bc] DomainSets v0.6.7
  [fa6b7ba4] DualNumbers v0.6.8
  [7c1d4256] DynamicPolynomials v0.5.3
  [4e289a0a] EnumX v1.0.4
  [f151be2c] EnzymeCore v0.6.4
  [460bff9d] ExceptionUnwrapping v0.1.9
  [d4d017d3] ExponentialUtilities v1.25.0
  [e2ba6199] ExprTools v0.1.10
  [c87230d0] FFMPEG v0.4.1
  [9d29842c] FastAlmostBandedMatrices v0.1.0
  [7034ab61] FastBroadcast v0.2.8
  [9aa1b823] FastClosures v0.3.2
  [29a986be] FastLapackInterface v2.0.0
  [1a297f60] FillArrays v1.9.3
  [6a86dc24] FiniteDiff v2.21.1
  [53c48c17] FixedPointNumbers v0.8.4
  [59287772] Formatting v0.4.2
  [f6369f11] ForwardDiff v0.10.36
  [069b7b12] FunctionWrappers v1.1.3
  [77dc65aa] FunctionWrappersWrappers v0.1.3
  [d9f16b24] Functors v0.4.5
⌃ [46192b85] GPUArraysCore v0.1.5
⌅ [28b8d3ca] GR v0.72.10
  [c145ed77] GenericSchur v0.5.3
  [c27321d9] Glob v1.3.1
  [86223c79] Graphs v1.9.0
  [42e2da0e] Grisu v1.0.2
  [0b43b601] Groebner v0.5.1
⌅ [d5909c97] GroupsCore v0.4.2
  [cd3eb016] HTTP v1.10.1
  [3e5b6fbb] HostCPUFeatures v0.1.16
  [34004b35] HypergeometricFunctions v0.3.23
  [615f187c] IfElse v0.1.1
  [d25df0c9] Inflate v0.1.4
  [18e54dd8] IntegerMathUtils v0.1.2
  [8197267c] IntervalSets v0.7.8
  [92d709cd] IrrationalConstants v0.2.2
  [82899510] IteratorInterfaceExtensions v1.0.0
  [1019f520] JLFzf v0.1.7
  [692b3bcd] JLLWrappers v1.5.0
  [682c06a0] JSON v0.21.4
  [98e50ef6] JuliaFormatter v1.0.45
  [ccbc3e58] JumpProcesses v9.10.1
  [ef3ab10e] KLU v0.4.1
  [ba0b0d4f] Krylov v0.9.5
  [b964fa9f] LaTeXStrings v1.3.1
  [2ee39098] LabelledArrays v1.15.0
  [984bce1d] LambertW v0.4.6
  [23fbe1c1] Latexify v0.16.1
  [10f19ff3] LayoutPointers v0.1.15
  [50d2b5c4] Lazy v0.15.1
  [5078a376] LazyArrays v1.8.3
  [2d8b4e74] LevyArea v1.0.0
  [d3d80556] LineSearches v7.2.0
  [7ed4a6bd] LinearSolve v2.22.0
  [2ab3a3ac] LogExpFunctions v0.3.26
  [e6f89c97] LoggingExtras v1.0.3
  [bdcacae8] LoopVectorization v0.12.166
  [d8e11817] MLStyle v0.4.17
  [1914dd2f] MacroTools v0.5.12
  [d125e4d3] ManualMemory v0.1.8
  [a3b82374] MatrixFactorizations v2.1.0
  [bb5d69b7] MaybeInplace v0.1.1
  [739be429] MbedTLS v1.1.9
  [442fdcdd] Measures v0.3.2
  [e1d29d7a] Missings v1.1.0
  [961ee093] ModelingToolkit v8.74.1
  [46d2c3a1] MuladdMacro v0.2.4
  [102ac46a] MultivariatePolynomials v0.5.3
  [d8a4904e] MutableArithmetics v1.4.0
  [d41bc354] NLSolversBase v7.8.3
  [2774e3e8] NLsolve v4.5.1
  [77ba4419] NaNMath v1.0.2
  [8913a72c] NonlinearSolve v3.4.0
  [6fe1bfb0] OffsetArrays v1.13.0
  [4d8831e6] OpenSSL v1.4.1
  [429524aa] Optim v1.7.8
  [bac558e1] OrderedCollections v1.6.3
  [1dea7af3] OrdinaryDiffEq v6.65.0
  [90014a1f] PDMats v0.11.31
  [65ce6f38] PackageExtensionCompat v1.0.2
  [d96e819e] Parameters v0.12.3
  [69de0a69] Parsers v2.8.1
  [b98c9c47] Pipe v1.3.0
  [ccf2f8ad] PlotThemes v3.1.0
  [995b91a9] PlotUtils v1.4.0
  [91a5bcdd] Plots v1.39.0
  [e409e4f3] PoissonRandom v0.4.4
  [f517fe37] Polyester v0.7.9
  [1d0040c9] PolyesterWeave v0.2.1
  [85a6dd25] PositiveFactorizations v0.2.4
  [d236fae5] PreallocationTools v0.4.13
  [aea7be01] PrecompileTools v1.2.0
  [21216c6a] Preferences v1.4.1
  [08abe8d2] PrettyTables v2.3.1
  [27ebfcd6] Primes v0.5.5
  [1fd47b50] QuadGK v2.9.1
  [74087812] Random123 v1.6.2
  [fb686558] RandomExtensions v0.4.4
  [e6cf234a] RandomNumbers v1.5.3
  [3cdcf5f2] RecipesBase v1.3.4
  [01d81517] RecipesPipeline v0.6.12
  [731186ca] RecursiveArrayTools v3.2.8
  [f2c3362d] RecursiveFactorization v0.2.21
  [189a3867] Reexport v1.2.2
  [05181044] RelocatableFolders v1.0.1
  [ae029012] Requires v1.3.0
  [ae5879a3] ResettableStacks v1.1.1
  [79098fc4] Rmath v0.7.1
  [7e49a35a] RuntimeGeneratedFunctions v0.5.12
  [fdea26ae] SIMD v3.4.6
  [94e857df] SIMDTypes v0.1.0
  [476501e8] SLEEFPirates v0.6.42
  [0bca4576] SciMLBase v2.11.7
  [c0aeaf25] SciMLOperators v0.3.7
  [6c6a2e73] Scratch v1.2.1
  [efcf1570] Setfield v1.1.1
  [992d4aef] Showoff v1.0.3
  [777ac1f9] SimpleBufferStream v1.1.0
  [727e6d20] SimpleNonlinearSolve v1.2.0
  [699a6c99] SimpleTraits v0.9.4
  [ce78b400] SimpleUnPack v1.1.0
  [a2af1166] SortingAlgorithms v1.2.0
  [47a9eef4] SparseDiffTools v2.15.0
  [e56a9233] Sparspak v0.3.9
  [276daf66] SpecialFunctions v2.3.1
  [aedffcd0] Static v0.8.8
  [0d7ed370] StaticArrayInterface v1.5.0
  [90137ffa] StaticArrays v1.8.1
  [1e83bf80] StaticArraysCore v1.4.2
  [82ae8749] StatsAPI v1.7.0
  [2913bbd2] StatsBase v0.34.2
  [4c63d2b9] StatsFuns v1.3.0
  [9672c7b4] SteadyStateDiffEq v2.0.1
  [789caeaf] StochasticDiffEq v6.64.0
  [7792a7ef] StrideArraysCore v0.5.2
  [892a3eda] StringManipulation v0.3.4
  [c3572dad] Sundials v4.23.1
  [2efcf032] SymbolicIndexingInterface v0.3.0
  [d1185830] SymbolicUtils v1.5.0
  [0c5d862f] Symbolics v5.13.0
  [3783bdb8] TableTraits v1.0.1
  [bd369af6] Tables v1.11.1
  [62fd8b95] TensorCore v0.1.1
  [8290d209] ThreadingUtilities v0.5.2
  [a759f4b9] TimerOutputs v0.5.23
  [0796e94c] Tokenize v0.5.26
  [3bb67fe8] TranscodingStreams v0.10.2
  [d5829a12] TriangularSolve v0.1.20
  [410a4b4d] Tricks v0.1.8
  [781d530d] TruncatedStacktraces v1.4.0
  [5c2747f8] URIs v1.5.1
  [3a884ed6] UnPack v1.0.2
  [1cfade01] UnicodeFun v0.4.1
  [1986cc42] Unitful v1.19.0
  [45397f5d] UnitfulLatexify v1.6.3
  [a7c27f48] Unityper v0.1.6
  [41fe7b60] Unzip v0.2.0
  [3d5dd08c] VectorizationBase v0.21.65
  [19fa3120] VertexSafeGraphs v0.2.0
  [6e34b625] Bzip2_jll v1.0.8+0
  [83423d85] Cairo_jll v1.16.1+1
  [2702e6a9] EpollShim_jll v0.0.20230411+0
  [2e619515] Expat_jll v2.5.0+0
  [b22a6f82] FFMPEG_jll v4.4.4+1
  [a3f928ae] Fontconfig_jll v2.13.93+0
  [d7e528f0] FreeType2_jll v2.13.1+0
  [559328eb] FriBidi_jll v1.0.10+0
  [0656b61e] GLFW_jll v3.3.9+0
⌅ [d2c73de3] GR_jll v0.72.10+0
  [78b55507] Gettext_jll v0.21.0+0
  [7746bdde] Glib_jll v2.76.5+0
  [3b182d85] Graphite2_jll v1.3.14+0
  [2e76f6c2] HarfBuzz_jll v2.8.1+1
  [1d5cc7b8] IntelOpenMP_jll v2024.0.2+0
  [aacddb02] JpegTurbo_jll v3.0.1+0
  [c1c5ebd0] LAME_jll v3.100.1+0
  [88015f11] LERC_jll v3.0.0+1
  [1d63c593] LLVMOpenMP_jll v15.0.7+0
  [dd4b983a] LZO_jll v2.10.1+0
⌅ [e9f186c6] Libffi_jll v3.2.2+1
  [d4300ac3] Libgcrypt_jll v1.8.7+0
  [7e76a0d4] Libglvnd_jll v1.6.0+0
  [7add5ba3] Libgpg_error_jll v1.42.0+0
  [94ce4f54] Libiconv_jll v1.17.0+0
  [4b2f31a3] Libmount_jll v2.35.0+0
⌅ [89763e89] Libtiff_jll v4.5.1+1
  [38a345b3] Libuuid_jll v2.36.0+0
  [856f044c] MKL_jll v2024.0.0+0
  [e7412a2a] Ogg_jll v1.3.5+1
  [458c3c95] OpenSSL_jll v3.0.12+0
  [efe28fd5] OpenSpecFun_jll v0.5.5+0
  [91d4177d] Opus_jll v1.3.2+0
  [30392449] Pixman_jll v0.42.2+0
  [c0090381] Qt6Base_jll v6.5.3+1
  [f50d1b31] Rmath_jll v0.4.0+0
⌅ [fb77eaff] Sundials_jll v5.2.2+0
  [a44049a8] Vulkan_Loader_jll v1.3.243+0
  [a2964d1f] Wayland_jll v1.21.0+1
  [2381bf8a] Wayland_protocols_jll v1.25.0+0
  [02c8fc9c] XML2_jll v2.12.2+0
  [aed1982a] XSLT_jll v1.1.34+0
  [ffd25f8a] XZ_jll v5.4.5+0
  [f67eecfb] Xorg_libICE_jll v1.0.10+1
  [c834827a] Xorg_libSM_jll v1.2.3+0
  [4f6342f7] Xorg_libX11_jll v1.8.6+0
  [0c0b7dd1] Xorg_libXau_jll v1.0.11+0
  [935fb764] Xorg_libXcursor_jll v1.2.0+4
  [a3789734] Xorg_libXdmcp_jll v1.1.4+0
  [1082639a] Xorg_libXext_jll v1.3.4+4
  [d091e8ba] Xorg_libXfixes_jll v5.0.3+4
  [a51aa0fd] Xorg_libXi_jll v1.7.10+4
  [d1454406] Xorg_libXinerama_jll v1.1.4+4
  [ec84b674] Xorg_libXrandr_jll v1.5.2+4
  [ea2f1a96] Xorg_libXrender_jll v0.9.10+4
  [14d82f49] Xorg_libpthread_stubs_jll v0.1.1+0
  [c7cfdc94] Xorg_libxcb_jll v1.15.0+0
  [cc61e674] Xorg_libxkbfile_jll v1.1.2+0
  [e920d4aa] Xorg_xcb_util_cursor_jll v0.1.4+0
  [12413925] Xorg_xcb_util_image_jll v0.4.0+1
  [2def613f] Xorg_xcb_util_jll v0.4.0+1
  [975044d2] Xorg_xcb_util_keysyms_jll v0.4.0+1
  [0d47668e] Xorg_xcb_util_renderutil_jll v0.3.9+1
  [c22f9ab0] Xorg_xcb_util_wm_jll v0.4.1+1
  [35661453] Xorg_xkbcomp_jll v1.4.6+0
  [33bec58e] Xorg_xkeyboard_config_jll v2.39.0+0
  [c5fb5394] Xorg_xtrans_jll v1.5.0+0
  [3161d3a3] Zstd_jll v1.5.5+0
  [35ca27e7] eudev_jll v3.2.9+0
  [214eeab7] fzf_jll v0.43.0+0
  [1a1c6b14] gperf_jll v3.1.1+0
  [a4ae2306] libaom_jll v3.4.0+0
  [0ac62f75] libass_jll v0.15.1+0
  [2db6ffa8] libevdev_jll v1.11.0+0
  [f638f0a6] libfdk_aac_jll v2.0.2+0
  [36db933b] libinput_jll v1.18.0+0
  [b53b4c65] libpng_jll v1.6.40+0
  [f27f6e37] libvorbis_jll v1.3.7+1
  [009596ad] mtdev_jll v1.1.6+0
  [1270edf5] x264_jll v2021.5.5+0
  [dfaa095f] x265_jll v3.5.0+0
  [d8fb68d0] xkbcommon_jll v1.4.1+1
  [0dad84c5] ArgTools v1.1.1
  [56f22d72] Artifacts
  [2a0f44e3] Base64
  [ade2ca70] Dates
  [8ba89e20] Distributed
  [f43a241f] Downloads v1.6.0
  [7b1f6079] FileWatching
  [9fa8497b] Future
  [b77e0a4c] InteractiveUtils
  [4af54fe1] LazyArtifacts
  [b27032c2] LibCURL v0.6.4
  [76f85450] LibGit2
  [8f399da3] Libdl
  [37e2e46d] LinearAlgebra
  [56ddb016] Logging
  [d6f4376e] Markdown
  [a63ad114] Mmap
  [ca575930] NetworkOptions v1.2.0
  [44cfe95a] Pkg v1.10.0
  [de0858da] Printf
  [3fa0cd96] REPL
  [9a3f8284] Random
  [ea8e919c] SHA v0.7.0
  [9e88b42a] Serialization
  [1a1011a3] SharedArrays
  [6462fe0b] Sockets
  [2f01184e] SparseArrays v1.10.0
  [10745b16] Statistics v1.10.0
  [4607b0f0] SuiteSparse
  [fa267f1f] TOML v1.0.3
  [a4e569a6] Tar v1.10.0
  [8dfed614] Test
  [cf7118a7] UUIDs
  [4ec0a83e] Unicode
  [e66e0078] CompilerSupportLibraries_jll v1.0.5+1
  [deac9b47] LibCURL_jll v8.4.0+0
  [e37daf67] LibGit2_jll v1.6.4+0
  [29816b5a] LibSSH2_jll v1.11.0+1
  [c8ffd9c3] MbedTLS_jll v2.28.2+1
  [14a3606d] MozillaCACerts_jll v2023.1.10
  [4536629a] OpenBLAS_jll v0.3.23+2
  [05823500] OpenLibm_jll v0.8.1+2
  [efcefdf7] PCRE2_jll v10.42.0+1
  [bea87d4a] SuiteSparse_jll v7.2.1+1
  [83775a58] Zlib_jll v1.2.13+1
  [8e850b90] libblastrampoline_jll v5.8.0+1
  [8e850ede] nghttp2_jll v1.52.0+1
  [3f19e933] p7zip_jll v17.4.0+2
Info Packages marked with ⌃ and ⌅ have new versions available. Those with ⌃ may be upgradable, but those with ⌅ are restricted by compatibility constraints from upgrading. To see why use `status --outdated -m`

• Output of versioninfo()

julia> versioninfo()
Julia Version 1.10.0
Commit 3120989f39 (2023-12-25 18:01 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 12 × AMD Ryzen 5 5600G with Radeon Graphics
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, znver3)
  Threads: 17 on 12 virtual cores
Environment:
  JULIA_CONDAPKG_BACKEND = Null
  JULIA_NUM_THREADS = auto
  JULIA_PROJECT = @.
  JULIA_PYTHONCALL_EXE = C:\Users\sosiristseng\conda\python.exe
  JULIA_EDITOR = code

[sosiristseng]

Additional info:

The solution interface works.

ts = range(0.0, 10.0, length=101)
plot(ts, sol(ts, idxs=[fol.x, fol.RHS])', label=["x" "RHS"]) # OK

[ChrisRackauckas]

Yes, I plan to redo the plot recipe pretty soon. The symbolic interface has gotten good enough that like 90% of the code can be deleted. I'll try and do this today.

[ChrisRackauckas]

Fixed by SciML/SciMLBase.jl#572