Fitting multiple dependent variables with time less than zero

3 views (last 30 days)
Suppose I have a therapeutic d that modulates an endogenous substance e. I've a pd model of e (for the sake of argument, a constant synthesis rate, and a linear clearance). I've a pk model for d. I have some sort of model that has e interact and bind with d, and the bound complex has a different clearance rate than e alone. My dataset has therapeutic doses applied to subjects at time zero. But I have undosed data for t<0 - perhaps a dataset of a couple months for e leading into the dosing period. The earlier data helps me set the parameters pertaining to e.
But the fitting programs won't accept any data earlier than t=0. Is this correct? Is my workaround to bias all times so that all time values are positive, and to tell SB that the dose is delayed by this bias? Or can I tell SB to accept values of time less than zero?

Accepted Answer

Arthur Goldsipe
Arthur Goldsipe on 9 Jul 2019
Right now, SimBiology simulations always have to start at zero. So for your problem, you'd have to adjust the data with an offset so there are no negative times.

More Answers (0)


More Answers in the  SimBiology Community

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!