I am having trouble adding a categorical covariate with 6 levels into the PML model. I “wrote” the model with the graphical editor, the base model runs fine but adding covariates results in a horrendously long random effect statetment that NLME seems to choke on. Editing it in text mode to several shorter lines makes no difference. the model has 14 main PK parameters.
William, are you able to post the code, or better yet the project for us to look at in more detail? thanks, Simon.
the project is attached, it just hangs . [file name=thc_nonlin.phxproj size=1405970]Certara | Drug Development Solutions (1.34 MB)
Hello, What I found in your project is that the first model will run in PHX 1.3, but it takes about 3 minutes just for the first iteration to show in the status window and about 15 minutes to finish running. (I set the Stderr option to ‘none’ before executing since standard errors can take a long time.) For the second model, where the covariate is added, I can see in the text output that it is always ending with a Fortran exception, and the output shows that the initial estimates are corrupted after the 40th term. I tested this in our current version that we are working on for the next release and this is fixed for the next release. However, we are still looking for a workaround that will help you in the PHX 1.3 version. Regards, Linda Hughes