How can I set a variable in my workspace as a constant?

Hello everyone,

I'm building a model in Simulink and the size of a few of my state flows depend on a variable in my workspace. I set this variable once in my initialisation, before running the Simulink model. The variable won't change for the duration of the simulation, it's a constant. If I now try and integrate my state flow with a discrete time integrator, I get the error: The discrete time integration with variable state flows is not supported. To work around this problem I have tried to set the variable from my workspace to not "tunable" in my simulink model, which sadly does not have any effect.

Is there a way to let Matlab/Simulink know that the variable that I've set once at the beginning will not change for the duration of the simulation?

Thank you in advance! Tom

Answer 1

[Satyajeet Sasmal]

The link below shows you how to set a constant property so that it can be used later. And these values cannot be changed once set:

http://www.mathworks.com/help/matlab/matlab_oop/properties-with-constant-values.html

I hope this was helpful.

-Satya

[Walter Roberson]

But can these be used that way in Simulink? Simulink has its own peculiar ideas about what is constant or not.