The Run Options tab allows determining how Phoenix executes a model. For individual modeling, the jobs are always run locally using the run method Naive-pooled, which cannot be changed. Population modelers have many more run options.
Individual modeling run options
Population modeling run options
For detailed explanations of Maximum Likelihood Models run methods, see the “Run modes” section.
Individual modeling run options
The following options are displayed on the Run Options tab when the Population? box is unchecked.
In the N Iter field, type the maximum number of iterations to use with each modeling run (the default is 1000 and the maximum is 10,000).
Check the Sort Input? box to sort the input by subject and time values.
When checked, the data is automatically sorted by ID (up to 5 levels of ID) and then by Time (if the model is time-based). Unchecking this option will process the data in the order given in the input dataset. Therefore, if the same subject ID is present in the dataset but the records are not consecutive, they will be treated as two different subjects.
If a single ID entry within a column is non-numeric then the entire column is considered non-numeric, otherwise it is considered numeric. Note that non-numeric and numeric ID variables are sorted differently. For example, in numeric ID sorting, 2 comes before 10 but in non-numeric order 10 comes before 2.
If dosing information comes from a dosing worksheet (external or internal) then Sort Input? is automatically selected because of the need to merge the dosing and main worksheets. Similarly, if the model has a parameter worksheet that provides initial values, the Sort Input? option is automatically selected because it requires merging and thus sorting over sub-populations or individuals.
The Sort Input? option is available for population modeling as well.
From the Max ODE menu, select one of the ODE (ordinary differential equations) solver methods: matrix exponent, auto-detect, non-stiff DVERK, stiff, non-stiff DOPRI5.
For more on ODE methodology, see the “Differential Equations in NLME” section.
Standard errors for the parameter estimators for individual models are computed using the Hessian method and the Stderr menu specifies the method used to compute standard errors: none, Central Diff, or Forward Diff.
See the Standard Error discussion for population modeling for more details.
In the Confidence Level % field, enter the confidence interval percentage.
In the Partial Deriv dP field, enter the amount of perturbation to apply to parameters to obtain partial derivatives.
Enter the number of time steps in the P. D. Time Steps field.
Plots of the partial derivatives are spaced at this number of time values over the whole timeline. To get a coarse plot, specify a small number. To get a smoother plot, specify a larger number of steps.