In Example 8.19, we discussed how to refer to a group of variables with sequential names, such as varname1, varname2, varname3. This is trivial in SAS and can be done in R as we showed.It's also sometimes useful to refer to all variables which begin w...

In section 1.11.4 (p. 50), we discuss referring to lists of variables in a data set. In SAS, this can be done for variable stored in adjacent columns with the "var_x -- var_y" syntax and for variables with sequentially enumerated suffixes with the "va...