Outlier nomination (detection) and robust regression are computationally hard problems. This is all the more true when the number of variables and observations grow rapidly. Among all candidate methods, the two BACON (blocked adaptive computationally efficient outlier nominators) algorithms of Billor et al. (2000) have favorable computational characteristics as they require only a few model evaluations irrespective of the sample size. This makes them popular algorithms for multivariate outlier nomination/ detection and robust linear regression (in early 2021, Google Scholar reports more than 500 citations of the Billor et al. (2000) paper).
wbacon is a package for the R statistical software. It is aimed at medium to large data sets that can possibly have (sampling) weights (e.g., data from complex survey samples). The package has a user-friendly R interface (with plotting methods, etc.) and is written mainly in the C language (with OpenMP support for parallelization for performance reasons.
Available methods
wBACON() is for multivariate outlier nomination and robust estimation of location/ center and covariance matrixwBACON_reg() is for robust linear regression (the method is robust against outliers in the response variable and the model's design matrix)