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Built 2024-04-18 using NMsim


This vignettes aims at enabling you to use NMsim for the following purposes

  • Simulation with parameters modified from the estimated values

Vary parameter values

Sometimes we want to simulate with some modification to the estimated model. NMsim can make such user-specified modifications to the model before simulating through the list.sections argument.

The SAD study was run with a fast solution formulation. We want to see how a slower absorption rate would affect the PK prediction for the multiple dose regimen. In the model estimate, TVKA=2.17. We now try with a four times slower absorption:

simres <- NMsim(file.mod=file.mod
               ,dir.sims="~/NMsim_vignette" ## where to store simulation files

simres.slowabs <- NMsim(file.mod=file.mod,
                       ,dir.sims="~/NMsim_vignette" ## where to store simulation files
rbind(simres,simres.slowabs) |>

We used list.sections to modify the $PK section. We used it to append two lines. We could use it to modify any section in the model, and we could essentially do any modification. However, appending to $PK or $PRED is simple and often both robust and flexible enough.

That was a very spcific analysis of one specific KA value. It is often more convenient to control the numeric changes to the model using the simulation input data set rather than hard-coding numerical values into list.sections. The following tries a number of fold changes to KA.

dat.sim.varka <- egdt(dat.sim,data.table(KASCALE=c(1,4,10)))

simres.varka <- NMsim(file.mod=file.mod,
                     ,dir.sims="~/NMsim_vignette" ## where to store simulation files
labs(colour="Fold absorption prolongation")