Undefined Reference Error

See test/Hydraulic/debugging.jl

Ben Chung guided me to adding a continuous_events function that seems to have bug.

Author: mgithubk

test/Hydraulic/debugging.jl

@@ -0,0 +1,72 @@
+using ModelingToolkit, OrdinaryDiffEq, Test
+using ModelingToolkit: t_nounits as t, D_nounits as D
+import ModelingToolkitStandardLibrary.Hydraulic.IsothermalCompressible as IC
+import ModelingToolkitStandardLibrary.Blocks as B
+import ModelingToolkitStandardLibrary.Mechanical.Translational as T
+
+using ModelingToolkitStandardLibrary.Blocks: Parameter
+
+@component function Step(;
+    name, height = 1.0, offset = 0.0, start_time = 0.0, duration = Inf,
+    smooth = 1e-5)
+@named output = B.RealOutput()
+duration_numeric = duration
+pars = @parameters offset=offset start_time=start_time height=height duration=duration step_val(t) :: Bool = true
+equation = if smooth == false # use comparison in case smooth is a float
+    offset +
+    ifelse((step_val) & (t < start_time + duration), height, zero(height))
+ #   ifelse((start_time <= t) & (t < start_time + duration), height, zero(height))
+else
+    smooth === true && (smooth = 1e-5)
+    if duration_numeric == Inf
+        smooth_step(t, smooth, height, offset, start_time)
+    else
+        smooth_step(t, smooth, height, offset, start_time) -
+        smooth_step(t, smooth, height, zero(start_time), start_time + duration)
+    end
+end
+
+eqs = [
+    output.u ~ equation
+]
+
+compose(ODESystem(eqs, t, [], pars; name = name, continuous_events = [[t ~ start_time, t ~ start_time + duration] => ((i,u,p,c) -> i.ps[p.step_val]=false, [], [step_val], [step_val], nothing)]), [output])
+
+end
+
+#@testset "Fluid Domain and Tube" begin
+    function System(N; bulk_modulus, name)
+        pars = @parameters begin
+            bulk_modulus = bulk_modulus
+        end
+
+        systems = @named begin
+            fluid = IC.HydraulicFluid(; bulk_modulus)
+            stp = Step(; height = 2*101325, offset = 101325, start_time = 0.05, duration = Inf,
+                smooth = false)
+            src = IC.Pressure(;)
+            vol = IC.FixedVolume(; vol = 10.0)
+            res = IC.Tube(N; area = 0.01, length = 50.0)
+        end
+
+        eqs = [connect(stp.output, src.p)
+               connect(fluid, src.port)
+               connect(src.port, res.port_a)
+               connect(res.port_b, vol.port)]
+
+               ODESystem(eqs, t, [], pars; name, systems)
+    end
+
+    @named sys5_1 = System(2; bulk_modulus = 1e9)
+
+    sys5_1 = structural_simplify(sys5_1)
+
+    initialization_eqs = [sys5_1.vol.port.p ~ 101325,sys5_1.res.p1.port_a.dm ~ 0]
+    initsys5_1 = ModelingToolkit.generate_initializesystem(sys5_1;initialization_eqs)
+
+    initsys5_1 = structural_simplify(initsys5_1)
+    initprob5_1 = NonlinearProblem(initsys5_1, [t=>0])
+    initsol5_1 = solve(initprob5_1)
+
+    prob5_1 = ODEProblem(sys5_1, [], (0, 50); initialization_eqs)
+    sol5_1 = solve(prob5_1) # ERROR: UndefRefError: access to undefined reference

test/Hydraulic/isothermal_compressible.jl

@@ -28,7 +28,7 @@ NEWTON = NLNewton(check_div = false, always_new = true, max_iter = 100, relax =
                connect(src.port, res.port_a)
                connect(res.port_b, vol.port)]
 
-        ODESystem(eqs, t, [], pars; name, systems)
+               ODESystem(eqs, t, [], pars; name, systems)
     end
 
     @named sys1_2 = System(1; bulk_modulus = 2e9)