How to do model fitting in simbiology

Dear Simbiology community,

I got 1 problem when I tried to fit data in simbiology. I am doing a population model fitting.

I have 1 column called "body weight" in my dataset. In that case, one parameter called 'AC' in my model could have different values for different IDs (subjects) (AC=BC*body weight). How could I let simbiology know this parameter 'AC' could change for different IDs? Should I revise my dataset or add parameters in my model?

I appreciate if someone could provide answers in detail. Thanks in advance!

YZ

Answer 1

[Fulden Buyukozturk]

Hello,

You can "dose" Body Weight to achieve this:

• Set "body weight" column as a dose column - dose2 if you already have an actual dose in your dataset.
• Create a new species to represent body weight since only species can be dosed in SimBiology. Let's assume you call this species BW.
• Set the value of the parameter that represents bodyweight in the model using a repeated assignment rule bodyweight = BW and calculate AC with another repeated assignment rule as AC = BC*bodyweight.Note that it's important to use repeated assignment rules intead of an initial assingment rule. Since initial assingmentments are evaluated before dosing, using initial assigmnets can lead to problems.
• In fit data task/program, map the "body weight" data column with BW.

Please let me know if this helps.

Fulden

[Yu Zhuo]

Thanks so much for your rely. It helps me a lot.

However, what I learnt before is that rules (eg. repeated assignment rules you mentioned) are only used in simulation, not model fitting, could I do this as you suggested when I am doing model fitting and would like to get parameter estimation?

I am really new to simbiology and I will appreciate if you could answer my stupid question. Thanks!

YZ