ssp.glm                 Optimal Subsampling Methods for Generalized
                        Linear Models
ssp.glm.rF              Balanced Subsampling Methods for Generalized
                        Linear Models with Rare Features
ssp.quantreg            Optimal Subsampling Methods for Quantile
                        Regression Model
ssp.relogit             Optimal Subsampling for Logistic Regression
                        Model with Rare Events Data
ssp.softmax             Optimal Subsampling Method for Softmax
                        (multinomial logistic) Regression Model
subsampling             Optimal Subsampling Methods for Statistical
                        Models
