Hi all,

I’m looking through the documentation on ODESystems in ModelingToolkit and came across the `ctrls`

(control parameters) argument for ODESystems:

`ctrls`

Control parameters (some subset of`ps`

).

This sounds like something I’m after, but I can’t seem to find any examples in the documentation of this argument being used explicitly.

My questions:

- Are there any existing examples of how to use control variables like this for ODESystems?
- Can these control variables be any external function? Something like that exists here, but I don’t know if this works here too
- Since these control variables are a subset of the parameters, can any parameter be selected as a control variable after the model is built, or do these need to be defined beforehand?

Thanks!