fix: array parameters in nested @mtkmodel components

[baggepinnen]

attempt to close #2813

This only handles defaults that are a single Num, like r=r_def, it does not yet handle r_def being an expression with multiple variables

[github-actions]

Benchmark Results (Julia vlts)

Time benchmarks

	master	42688d5...	master / 42688d5...
ODEProblem	0.0858 ± 0.0071 s	0.0833 ± 0.0068 s	1.03 ± 0.12
init	0.0598 ± 0.0024 ms	0.0587 ± 0.0016 ms	1.02 ± 0.05
large_parameter_init/ODEProblem	1.11 ± 0.0016 s	1.11 ± 0.0037 s	0.999 ± 0.0037
large_parameter_init/init	0.111 ± 0.0044 ms	0.109 ± 0.0028 ms	1.01 ± 0.048
mtkcompile	0.0367 ± 0.0033 s	0.0378 ± 0.0016 s	0.971 ± 0.096
time_to_load	4.99 ± 0.026 s	5.08 ± 0.018 s	0.982 ± 0.0062

Memory benchmarks

	master	42688d5...	master / 42688d5...
ODEProblem	0.587 M allocs: 19.9 MB	0.587 M allocs: 19.9 MB	1
init	0.892 k allocs: 0.0463 MB	0.892 k allocs: 0.0463 MB	1
large_parameter_init/ODEProblem	4.32 M allocs: 0.168 GB	4.3 M allocs: 0.166 GB	1.01
large_parameter_init/init	1.74 k allocs: 0.0858 MB	1.74 k allocs: 0.0858 MB	1
mtkcompile	0.237 M allocs: 8.75 MB	0.243 M allocs: 9.02 MB	0.971
time_to_load	0.153 k allocs: 14.5 kB	0.153 k allocs: 14.5 kB	1

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	master	42688d5...	master / 42688d5...
ODEProblem	0.0793 ± 0.0041 s	0.0765 ± 0.0055 s	1.04 ± 0.092
init	0.0526 ± 0.012 ms	0.0524 ± 0.011 ms	1 ± 0.31
large_parameter_init/ODEProblem	1.09 ± 0.015 s	1.06 ± 0.021 s	1.03 ± 0.024
large_parameter_init/init	0.094 ± 0.0091 ms	0.0939 ± 0.01 ms	1 ± 0.15
mtkcompile	0.0344 ± 0.00098 s	0.0343 ± 0.00062 s	1 ± 0.034
time_to_load	4.92 ± 0.061 s	4.9 ± 0.044 s	1.01 ± 0.015

Memory benchmarks

	master	42688d5...	master / 42688d5...
ODEProblem	0.577 M allocs: 18.8 MB	0.578 M allocs: 18.8 MB	1
init	0.799 k allocs: 30.9 kB	0.799 k allocs: 30.9 kB	1
large_parameter_init/ODEProblem	4.39 M allocs: 0.16 GB	4.4 M allocs: 0.159 GB	1
large_parameter_init/init	1.65 k allocs: 0.0696 MB	1.65 k allocs: 0.0696 MB	1
mtkcompile	0.236 M allocs: 8.17 MB	0.242 M allocs: 8.38 MB	0.975
time_to_load	0.159 k allocs: 11.2 kB	0.159 k allocs: 11.2 kB	1

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	if isparameter(var_unwrapped) && !(var_unwrapped in sys_params || var_unwrapped in sys_unknowns)
	if isparameter(var_unwrapped) &&
	!(var_unwrapped in sys_params || var_unwrapped in sys_unknowns)

[github-actions]

[JuliaFormatter] _{reported by reviewdog 🐶}

Suggested change

	Dict((isparameter(k) ? parameters(sys, k) : unknowns(sys, k)) =>
	(should_namespace(v) ? namespace_expr(v, sys) : v)
	Dict((isparameter(k) ? parameters(sys, k) :
	unknowns(sys, k)) => (should_namespace(v) ? namespace_expr(v, sys) : v)

[AayushSabharwal]

Tests fail

[baggepinnen]

I don't think I have sufficient insight into the internals to make everything pass. This was enough to allow me to move forward on a time critical problem, so I'll probably leave it here for now

[AayushSabharwal]

Makes sense, I'll try and take a look when I can.

[baggepinnen]

Here's another test case that fails both on latest release and this PR branch, wrong number of defaults generated

using ModelingToolkit
using ModelingToolkit: t_nounits as t, D_nounits as D

@mtkmodel inner2 begin
    @parameters begin
        a[1:2] = a
    end
    @variables begin
        x(t)[1:2] = zeros(2)
    end
    @equations begin
        D(x) ~ a
    end
end

@mtkmodel outer2 begin
    @parameters begin
        a1 = 1
        a2 = 1
    end
    @components begin
        i = inner2(a=[a1,a2])
    end
    @variables begin
     y(t)[1:2] = zeros(2)
     dy(t)[1:2]
    end
    @equations begin
        D(y) ~ dy
        dy ~ [a1, a2]
    end
end

@named o = outer2()
o = complete(o)
ssys = mtkcompile(o)
varmap = []

prob = ODEProblem(ssys, varmap, (0, 1))

This looks fishy

julia> MTK=ModelingToolkit;filter(kvp -> !MTK.isinitial(kvp[1]) && !MTK.isparameter(kvp[1]), defaults(ssys))
Dict{Any, Any} with 6 entries:
  (i₊x(t))[2] => 0.0
  (i₊x(t))[1] => 0.0
  (y(t))[2]   => 0.0
  (y(t))[1]   => 0.0
  (dy(t))[2]  => NoValue()
  (dy(t))[1]  => NoValue()