Yingbo Ma

We haven't added array support yet, but we will.

First, `L` is not a SI unit; `m^3` is a SI unit. In principle, unit checking can pass as long as they have the same dimension, but what happens when...

There's no way of tell if someone uses constants like `u"cm"` or `1e-2u"m"` though. ```julia julia> using DynamicQuantities julia> u"cm" 0.01 m julia> 1e-2u"m" 0.01 m julia> 1e-2u"m" === u"cm"...

To support non-SI units, we need to use `SymbolicDimensions` from `DynamicQuantities`.

I don't think so. It just makes structural simplify to at least work.

Let's not merge this PR for now.

The formatter CI fails.

@ChrisRackauckas ```julia initsys = initializesystem(sys) ss = structural_simplify(initsys, fully_determined = false) initprob = NonlinearProblem(ss, [], check_length=false, checkbounds = true) lsqprob = NonlinearLeastSquaresProblem(NonlinearFunction(initprob.f.f, resid_prototype = zeros(length(equations(ss)))), initprob.u0, initprob.p) initsol = solve(lsqprob,...

Ah, of course.

Looks like we need to update the tests as well https://github.com/SciML/ModelingToolkit.jl/actions/runs/8443829319/job/23128226047?pr=2328#step:6:1037