The **smoothAPC** package implements smoothing of demographic data. The method uses bivariate thin plate splines, bivariate lasso-type regularization, and allows for both period and cohort effects. Thus the mortality rates are modelled as the sum of four components: a smooth bivariate function of age and time, smooth one-dimensional cohort effects, smooth one-dimensional period effects and random errors.

The methods are described in Dokumentov, A., and Hyndman, R.J. (2014) Bivariate data with ridges: two-dimensional smoothing of mortality rates.