Assigning value to time dependent symbolic function inside a function

General Usage
,
1

Hi,

In the following code:

using ModelingToolkit

@variables t 

@register_symbolic u(t)

u(t) = 60

is there a way I can assign a value to u(t) from inside a function? The following doesn’t work.

function assignValue(x)
	u(t) = x
end

assignValue(60)
2

What are you trying to accomplish? Given the information you have provided, you might as well do

@variables u(t)

equations = [
    u ~ 60
]
3

Hi, thanks for the response.

I want to simulate a modelingtoolkit model from python. Something like this:

# Importing the model
from julia import Main
Main.include("model.jl")

# Control input
u = 60

# Simulate
sol = Main.solveModel(u)

So, I want to be able to change the control input value from python.

4

If the input is always a constant, you can encode it as a parameter using @parameters and then change the value by providing a new value in the parameter map when creating the ODEProblem.

5

That worked! Thanks a lot :blush:

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