RC circuit demonstration doesn't work

[dodoplus]

The example uses ConstantVoltage which seems to be missing from latest release of the library.

Example is here: http://mtkstdlib.sciml.ai/dev/tutorials/rc_circuit/ as well as on the home page.

[kakila]

The sources have changed, you need to create the input voltage using Blocks

 using ModelingToolkit, DifferentialEquations, Plots
 using ModelingToolkitStandardLibrary.Electrical
 using ModelingToolkitStandardLibrary.Blocks: Constant

resistance = 1.0
capacitance = 1.0
voltage = 1.0
@variables t
@named R = Resistor(R=resistance)
@named C = Capacitor(C=capacitance)
@named V = Voltage()
@named ground = Ground()
@named source = Constant(k=voltage)

rc_eqs = [
connect(V.p, R.p)
connect(R.n, C.p)
connect(C.n, V.n, ground.g)
connect(V.V, source.output)
]
@named rc_model = ODESystem(rc_eqs, t, systems=[R, C, V, source, ground])

sys = structural_simplify(rc_model)

prob = ODEProblem(sys, Pair[], (0, 10.0), [R.R => _R], jac = true)
sol = solve(prob)

p = plot(sol, vars = [C.v,R.i],
	title = "RC Circuit Demonstration",
	labels = ["Capacitor Voltage" "Resistor Current"])

[ChrisRackauckas]

@ValentinKaisermayer can you enable doctests? That would've caught this.

[ValentinKaisermayer]

I will do that. Should we add the electrical sources as explicit components as well?

[ChrisRackauckas]

What do you mean?

[ValentinKaisermayer]

The last PR removed a bunch of sources from Electrical (hence it was breaking), should we add those back in?

[ChrisRackauckas]

yeah that should've been a breaking release. I know this is all a little loose since the library is still in its infant days, but we should start be clean up this repo a bit and make it properly deprecate deletions.

[ValentinKaisermayer]

so should we add the sources back in?

[ChrisRackauckas]

We might be fine this time, but this is the turning point. You did something breaking and two people instantly noticed it. If two people noticed it in hours, that means that the library has quite a bit of uptake by now. That's actually a bit surprising to me (I thought it was still in the "early pre-adoption phase"), but this makes it clear that it's adopted so it needs to start following the standard practices associated with a library people are have put into their dependency tree.

And on this note, I should probably prepare a release announcement 😅

[ValentinKaisermayer]

Can be closed