Fig. 2.

Basic goodness-of-fit plots for the final isoniazid population pharmacokinetic model. a, b The observed concentrations plotted against the model-predicted concentrations or the individual model-predicted concentrations. The black lines represent the line of unity, and the blue lines represent the local polynomial regression fit. c The conditionally weighted residuals plotted against the time after dose. The solid lines are the y = 0 lines, and the dashed lines define the range between which you want the majority of the observations to lie. d The normalised prediction distribution errors plotted against the time after dose. The solid lines are the y = 0 lines and the blue lines are the means per time bin