Thanks for the great work to make modeling in R more usable!
> On Nov 9, 2017, at 07:42, Wang, Wenping <[email protected]> wrote: > > The nlmixr team is very proud to announce the first CRAN release of nlmixr > (https://cran.r-project.org/web/packages/nlmixr/), an open source package for > population PK and PKPD modelling. nlmixr builds on the RxODE package for > simulation of nonlinear mixed effect models using ordinary differential > equations, by implementing parameter estimation algorithms like nlme and SAEM > (with gnlmm and FOCEi under active development). nlmixr greatly expands the > utility of existing packages (like nlme) by providing an efficient and > versatile way to specify pharmacometric models and dosing scenarios, with > rapid execution due to compilation to C++. > > This new release features a unified user-interface. This user-interface > provides PKPD modelers a minimalist, intuitive, expressive, domain-specific > modeling language to compactly describe the model structure & efficiently > explore the population data at hand. Below is an example of specifying the > theophline data by this domain language: > > f <- function(){ > ini({ > lCl <- -3 # log Cl (L/hr) > lVc <- -1 # log Vc (L) > lKA <- 1 # log Ka (1/hr) > add.err <- c(0, 0.2, 1) > eta.Cl ~ 0.1 # BSV Cl > eta.Vc ~ 0.1 # BSV Vc > eta.KA ~ 0.1 # BSV Ka > }) > model({ > ## First parameters are defined in terms of the initial estimates > ## parameter names. > Cl <- exp(lCl + eta.Cl) > Vc <- exp(lVc + eta.Vc) > KA <- exp(lKA + eta.KA) > ## Next, the differential equations are defined > d/dt(depot) = -KA*depot; > d/dt(centr) = KA*depot-Cl/Vc*centr; > ## And the concentration is then calculated > cp = centr / Vc; > ## Last, nlmixr is told that the plasma concentration follows > ## an additive error (estimated by the parameter add.err) > cp ~ add(add.err) > }) > } > > fit <- nlmixr(f, theo_sd, est="saem") > plot(fit) > > Get in touch, reach out to us and discuss ways you could contribute, or try > it out for yourself, and experience the joy of exploring and modelling > population data all within R! The nlmixr team is working hard to make this > community based modeling tool even better. Our goal: Express your model in > nlmixr, openly and freely. > > Wenping Wang, PhD > Executive Director, Pharmacometrics > Novartis Pharmaceuticals Corporation > One Health Plaza, East Hanover, NJ 07936-1080, USA > Phone +1 862 7789009; Fax +1 9737818265
