Produces separate statistics for each BY group.
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BY <DESCENDING> variable-1 <...<DESCENDING>
variable-n> <NOTSORTED>;
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variable
-
specifies the variable that the procedure
uses to form BY groups. You can specify more than one variable. If you omit
the NOTSORTED option in the BY statement, then the observations in the data
set either must be sorted by all the variables that you specify or must be
indexed appropriately. Variables in a BY statement are called BY variables.
-
DESCENDING
-
specifies that the observations are 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 observations are sorted 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. 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, then the procedure
treats each contiguous set as a separate BY group.
If you use the BY statement with the SAS system option NOBYLINE,
which suppresses the BY line that normally appears in output that is produced
with BY-group processing, then PROC MEANS always starts a new page for each
BY group. This behavior ensures that if you create customized BY lines by
putting BY-group information in the title and suppressing the default BY lines
with NOBYLINE, then the information in the titles matches the report on the
pages. (See Creating Titles That Contain BY-Group Information and
Suppressing the Default BY Line.)
Copyright © 2010 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
