Using MTK when I *import* ModelingToolkit?

Specific Domains Modelling & Simulations
1

I have some ModelingToolkit model that works when importing via using. Because of a name conflict, I need to import MTK as import ModelingToolkit as mtk instead. The following code works with using.... What modifications do I need to do if I use import...?

using ModelingToolkit
using ModelingToolkit: t_nounits as t, D_nounits as D
using OrdinaryDiffEq
#
@mtkmodel Model begin
    @structural_parameters begin
        nonlinear = true
    end
    #
    @parameters begin
        a = 2
        b = 3
    end
    #
    @variables begin
        x(t) = 1
    end
    @equations begin
        if nonlinear
            D(x) ~ -a*x -b*x^3
        else
            D(x) ~ -a*x
        end
    end
end
#
@mtkcompile m_n = Model()
@mtkcompile m_L = Model(;nonlinear=false)

This works.

When I change using ModelingToolkit to import ModelingToolkit as mtk, do I also need to do something with the import of time and derivative?

What about the macros? Do I need to change @mtkmodel to @mtk.mtkmodel? What about @parameters, etc.?

2

You need to somehow import all symbols, you can list the macros also in the using statements, like

using ModelingToolkit: t_nounits as t, D_nounits as D, @mtkmodel, @structural_parameters, @parameters

and so on

3

I do:

using ModelingToolkit: @mtkmodel, @structural_parameters, @parameters, @variables, @equations, @mtkcompile
using ModelingToolkit: t_nounits as t, D_nounits as D
using OrdinaryDiffEq

and get warnings:

WARNING: Imported binding ModelingToolkit.@structural_parameters was undeclared at import time during import to Main.
WARNING: Imported binding ModelingToolkit.@equations was undeclared at import time during import to Main.

Next, doing

@mtkcompile m_n = Model()
@mtkcompile m_L = Model(;nonlinear=false)

produces error message:

UndefVarError: `ModelingToolkit` not defined in `Main`
Suggestion: check for spelling errors or missing imports.
Hint: ModelingToolkit is loaded but not imported in the active module Main.

Stacktrace:
 [1] __Model__(; name::Symbol, nonlinear::Bool, a::ModelingToolkit.NoValue, b::ModelingToolkit.NoValue, x::ModelingToolkit.NoValue)
   @ Main C:\Users\Bernt\.julia\packages\ModelingToolkit\b28X4\src\systems\model_parsing.jl:159
 [2] __Model__
   @ C:\Users\Bernt\.julia\packages\ModelingToolkit\b28X4\src\systems\model_parsing.jl:159 [inlined]
 [3] #_#432
   @ C:\Users\Bernt\.julia\packages\ModelingToolkit\b28X4\src\systems\model_parsing.jl:25 [inlined]
 [4] top-level scope
   @ C:\Users\Bernt\.julia\packages\ModelingToolkit\b28X4\src\systems\abstractsystem.jl:2152
4

Hm. I decided it was probably simpler to do using ModelingToolkit and instead import the other package as import Molly as mly. The conflict between these is that both appear to expose a System constructor.