An implementation of the surrogate approach to residuals and diagnostics for ordinal and general regression models; for details, see Liu and Zhang (2017) <doi:10.1080/01621459.2017.1292915>. These residuals can be used to construct standard residual plots for model diagnostics (e.g., residual-vs-fitted value plots, residual-vs-covariate plots, Q-Q plots, etc.). The package also provides an autoplot function for producing standard diagnostic plots using ggplot2 graphics. The package currently supports cumulative link models from packages MASS', ordinal', rms', and VGAM'. Support for binary regression models using the standard glm function is also available.