concentration range for ecxsys()
Idea for a new argument: Set the maximum concentration for the curves data frame. Maybe the observed concentrations only go to 10 but I would like to see the curves go to 30. Should be easy to implement. But leave the default value at NULL to use the current behaviour.
There is also an idea of setting the minimum concentration for the prediction of the control. But I'm not sure how I would implement that from a usability perspective, or if I even should.