The SUMBY statement produces consolidation tables for variables whose names are in the SUMBY list. Only one SUMBY statement can be used.

To use a SUMBY statement, you must use a BY statement. The SUMBY and BY variables must be in the same relative order in both statements. For example:

   by a b c;
   sumby a b;

This SUMBY statement produces tables that consolidate over values of C within levels of B and over values of B within levels of A. Suppose A has values 1, 2; B has values 1, 2; and C has values 1, 2, 3. Table 9.2 indicates the consolidation tables produced by the SUMBY statement.

Two consolidation tables for B are produced for each value of A. The first table consolidates the three tables produced for the values of C while B is 1; the second table consolidates the three tables produced for C while B is 2.

Tables are similarly produced for values of A. Nested consolidation tables are produced for B (as described previously) for each value of A. Thus, this SUMBY statement produces a total of six consolidation tables in addition to the tables produced for each BY group.

To produce a table that consolidates the entire data set (the equivalent of using PROC COMPUTAB with neither BY nor SUMBY statements), use the special name _TOTAL_ as the first entry in the SUMBY variable list. For example,

   sumby _total_ a b;

PROC COMPUTAB then produces consolidation tables for SUMBY variables as well as a consolidation table for all observations.

To produce only consolidation tables, use the SUMONLY option in the PROC COMPUTAB statement.