access to undefined reference in reset_fsal!

[baggepinnen]

Not sure if MTK or OrdinaryDiffEq, but

using ModelingToolkit, OrdinaryDiffEq

@component function ContactForce(; name, surface=nothing)
    systems = @named begin
        # frame_a = Frame()
        # frame_b = Frame()
        # q = RealInput()
        # force = Force()
    end
    vars = @variables begin
        q(t) = 1
        v(t) = 0
        f(t)
        h(t)
        hd(t)
        hdd(t)
        λ(t)=0
    end
    pars = @parameters begin
        contact::Int = 0    # discrete.time state variable
        b1::Bool=false      # discrete.time state variable
        b2::Bool=false      # discrete.time state variable
        b3::Bool=false      # discrete.time state variable
        b4::Bool=false      # discrete.time state variable
        a0 = 100
        a1 = 20
        a2 = 1e6
        linFlag::Bool = false
    end

    function affect!(integ, u, p, _)
        h = integ.u[u.h]
        hd = integ.u[u.hd]
        λ = integ.u[u.λ]

        b1_old = integ.p[p.b1]
        b2_old = integ.p[p.b2]
        b3_old = integ.p[p.b3]
        b4_old = integ.p[p.b4]

        b1 = h <= 0
        b2 = λ < 0
        b3 = h > 0
        b4 = h <= 0 && hd < 0

        contact = integ.p[p.contact]
        integ.p[p.b1] = b1
        integ.p[p.b2] = b2
        integ.p[p.b3] = b3
        integ.p[p.b4] = b4

        edge_b1 = b1 != b1_old
        edge_b2 = b2 != b2_old
        edge_b3 = b3 != b3_old
        edge_b4 = b4 != b4_old

        if contact == 0 && edge_b1
            contact = 1
        end
        if contact == 1 && edge_b2
            contact = 2
        end
        if contact == 2 && edge_b3
            contact = 0
        end
        if contact == 2 && edge_b4
            contact = 1
        end
        integ.p[p.contact] = contact
    end
    
    equations = [
        0 ~ ifelse((contact == 1) | (linFlag == true), hdd + a1*hd + a0*h + a2*h^3, λ)
        f ~ ifelse(linFlag == true, λ, contact*λ)
        D(q) ~ v

        1 * D(v) ~ -1 * 9.81 + f # Temp

        h ~ q
        hd ~ D(h)
        hdd ~ D(hd)
    ]

    continuous_events = [h ~ 0, λ ~ 0] => (affect!, [h, hd, λ], [b1,b2,b3,b4,contact], [b1,b2,b3,b4,contact], nothing)
    ODESystem(equations, t, vars, pars; name, systems, continuous_events)
end

@named model = ContactForce()
model = complete(model)
ssys = structural_simplify(model)
prob = ODEProblem(ssys, [], (0.0, 5.0))
sol = solve(prob)

julia> sol = solve(prob)
ERROR: UndefRefError: access to undefined reference
Stacktrace:
  [1] getproperty
    @ ./Base.jl:37 [inlined]
  [2] reset_fsal!
    @ ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/integrators/integrator_utils.jl:485 [inlined]
  [3] apply_step!(integrator::OrdinaryDiffEqCore.ODEIntegrator{…})
    @ OrdinaryDiffEqCore ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/integrators/integrator_utils.jl:410
  [4] loopheader!(integrator::OrdinaryDiffEqCore.ODEIntegrator{…})
    @ OrdinaryDiffEqCore ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/integrators/integrator_utils.jl:14
  [5] solve!(integrator::OrdinaryDiffEqCore.ODEIntegrator{…})
    @ OrdinaryDiffEqCore ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/solve.jl:547
  [6] __solve(::ODEProblem{…}, ::CompositeAlgorithm{…}; kwargs::@Kwargs{…})
    @ OrdinaryDiffEqCore ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/solve.jl:7
  [7] __solve
    @ ~/.julia/packages/OrdinaryDiffEqCore/4A2vD/src/solve.jl:1 [inlined]
  [8] solve_call(_prob::ODEProblem{…}, args::CompositeAlgorithm{…}; merge_callbacks::Bool, kwargshandle::Nothing, kwargs::@Kwargs{…})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:612
  [9] solve_call
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:569 [inlined]
 [10] solve_up(prob::ODEProblem{…}, sensealg::Nothing, u0::Vector{…}, p::MTKParameters{…}, args::CompositeAlgorithm{…}; kwargs::@Kwargs{…})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1080
 [11] solve_up
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1066 [inlined]
 [12] #solve#51
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1003 [inlined]
 [13] solve
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:993 [inlined]
 [14] #__solve#3
    @ ~/.julia/packages/OrdinaryDiffEqDefault/2qVWT/src/default_alg.jl:46 [inlined]
 [15] __solve
    @ ~/.julia/packages/OrdinaryDiffEqDefault/2qVWT/src/default_alg.jl:45 [inlined]
 [16] #__solve#72
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1394 [inlined]
 [17] __solve
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1386 [inlined]
 [18] solve_call(::ODEProblem{…}; merge_callbacks::Bool, kwargshandle::Nothing, kwargs::@Kwargs{})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:612
 [19] solve_call
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:569 [inlined]
 [20] #solve_up#53
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1072 [inlined]
 [21] solve_up
    @ ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1066 [inlined]
 [22] solve(::ODEProblem{…}; sensealg::Nothing, u0::Nothing, p::Nothing, wrap::Val{…}, kwargs::@Kwargs{})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:1003
 [23] solve(::ODEProblem{…})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/sCsah/src/solve.jl:993
 [24] top-level scope
    @ REPL[150]:1
Some type information was truncated. Use `show(err)` to see complete types.

This appears to be a problem with the default alg, if I specify Rodas4() as the solver it works out.

OrdinaryDiffEqCore v1.3.0
ModelingToolkit v9.33.1 and master

[oscardssmith]

will fix