The UNIVARIATE Procedure

BY Statement

  • BY variables;

You can specify a BY statement with PROC UNIVARIATE to obtain separate analyses for each BY group. The BY statement specifies the variables that the procedure uses to form BY groups. You can specify more than one variable. If you do not use the NOTSORTED option in the BY statement, the observations in the data set must either be sorted by all the variables that you specify or be indexed appropriately.

DESCENDING

specifies that the data set is sorted in descending order by the variable that immediately follows the word DESCENDING in the BY statement.

NOTSORTED

specifies that observations are not necessarily sorted in alphabetic or numeric order. The data are grouped in another way—for example, chronological order.

The requirement for ordering or indexing observations according to the values of BY variables is suspended for BY group processing when you use the NOTSORTED option. In fact, the procedure does not use an index if you specify NOTSORTED. The procedure defines a BY group as a set of contiguous observations that have the same values for all BY variables. If observations with the same values for the BY variables are not contiguous, the procedure treats each contiguous set as a separate BY group.