The mgcViz R package offers visual tools for Generalized Additive Models (GAMs). The visualizations provided by mgcViz differs from those implemented in mgcv, in that most of the plots are based on ggplot2’s powerful layering system. This has been implemented by wrapping several ggplot2 layers and integrating them with computations specific to GAM models. Further, mgcViz uses binning and/or sub-sampling to produce plots that can scale to large datasets (n = O(10^7)), and offers a variety of new methods for visual model checking/selection.

See the vignette for an introduction to the following categories of visualizations:

  1. smooth and parametric effect plots: layered plots based on ggplot2 and interactive 3d visualizations based on the rgl library;

  2. model checks: interactive QQ-plots, traditional residuals plots and layered residuals checks along one or two covariates;

  3. special plots: differences-between-smooths plots in 1 or 2D and plotting multiple slices of multidimensional smooth effects.