I’m trying to fit the same model to a rather large in vitro dataset with multiple cancer cell lines and compounds - I want to fit each compound/cell-line combination separately, but using the same structural model for each, then compare parameter values within cell-lines or across compounds. There’s no rationale for assuming a population model (cancer cell lines can be widely dissimilar, even for the “same” disease), so a double-sort seemed the way to go. And that works fine when I’m fitting a model for (exponential) growth in medium (no compound).
But what I need to do next is take those no-compound growth rates, and keep them fixed while I fit the compound effect at various concentrations. I’ve tried linking those estimates into ‘Parameters’ and setting up the ‘Parameters.Mapping’. I’m using the same sort as in the no-compound model, but it just seems to take the first value for each parameter, rather than taking the one for the right cell-line. (You might think that you’ve figured it out - there’s only a single value of each parameter for each cell-line in the no-compound model, so how can there be a double-sort? Well, I figured that out on my own, and realized I had to duplicate the fit parameters, so that each compound has it’s own zero-concentration value, which will be the same as that for all the other compounds. So that’s not the issue here.)
I must admit, I’m a little unclear on how the override function is used - I’m not using it, but feel this might be part of the solution. I’ve checked the manual, and it has very little to say, other than that ‘override’ is a reserved keyword!
Anyone have any ideas, either on the modeling problem, or the ‘override’ keyword?
-Frank