A Semiparametric Nonlinear Mixed Effects Model with Penalized Splines Using Automatic Differentiation
We present an estimation procedure for nonlinear mixed-effects models in which the population trajectory is represented by penalized splines and adapted to individuals via subject-specific transformation parameters. By exploiting the mixed model representation of penalized splines, the level of smoothness can be estimated jointly with other variance components. The approach is illustrated through a case study on infant height growth. arXiv preprint.