Is there a way of performing a nlinfit with 2 independent variables in SimBiology?

Hello,

I'm building a TMDD PK model using SimBiology. I need to estimate the model parameters using time-courses with 2 independent variables (time + one parameter which value is known but varies for each time course). Can this be done using SimBiology GUI, SimBiology CLI? If not, can this be done using other MATLAB apps? Is there any tutorial? Thanks for your help!

Antonio

Answer 1

[Arthur Goldsipe]

Hi,

SimBiology does not support this kind of problem in the desktop GUI or in the command-line functions like sbiofit. Today, the only other "independent variables" that are supported are dosing. I can think of two workarounds for this limitation:

One workaround would be to implement the different parameter values using fake dosing data. For example, let's assume one time course uses parameter k=3 and another uses parameter k=5. Since doses can only modify species, you could introduce a species "doseK" and a repeated assignment rule "k=doseK" with one time course having a dose amount of 3 at time=0 and another having a dose amount of 5 at time=0.

Another workaround would be to write your own objective function to use for estimation. Inside your objective function, you can then simulate the model with each of the known parameter values. This requires more work but gives you the most flexibility.

If you have additional questions, I recommend contacting me directly or emailing Tech Support, since I don't get notified if you post comments to my reply.

Best of luck,

Arthur

[dschubba]

Thanks Arthur.