A grouped version of gau with an additional group label column.
Format
A data frame with 5,000 rows and 21 columns. The first 20 columns,
named V1, V2, ..., V20, are the numerical variables from gau.
The last column, group, is a group label with values group1, group2,
group3, group4, and group5.
Details
The dataset contains the same 5,000 observations and 20 numerical variables
as gau, together with a group label column. There are five groups, and
each group contains 1,000 observations.