When clicking on the “Check init.”, the predictions obtained with the initial values are displayed for each individual together with the data points. This feature is very useful to find some “good” initial values. You can change the values of the parameters and see how the agreement with the data change. In addition, you can change the axis to log-scale and choose the same limit on all axis to have a better comparison of the individuals.
On the bottom (in the green box), you have all the parameters and can play with them and see directly the impact on the prediction (in red) for each individual. In addition, there is an “AUTO-INIT” button (on the blue block on the right). It allows to provide automatically a good estimate of all the parameters as in the following example. If in addition, you click on “SET AS INITIAL VALUES”, it set these parameters as initial values for the calculation and you go back to the settings for the CA parameters calculation.