Multiple Numeric Indices (VARSTOCASES command)

Multiple numeric indices are used to identify groups of new rows that share a particular combination of factors. You can create multiple numeric indices if the original variables are ordered so that levels of a given factor are grouped together.

• The basic specification is /INDEX=ivar(n) ivar(n) ..., where ivar is the name of the new index for a factor and n is the number of factor levels represented in the variable group for which the index is being constructed.
• The last index specified varies the fastest.

Example

       B1      B2

A1    .00     .05

A2   5.00    3.00

• Data were collected for a designed experiment with two levels of factor A and two levels of factor B. The table shows the data for the first case.

  caseid     v_a1b1    v_a1b2    v_a2b1    v_a2b2
  001           .00       .05      5.00      3.00

• The original data file is structured so that each case has one variable for each combination of factors. Note that factor B varies fastest.

  VARSTOCASES 
  	/MAKE newvar FROM v_a1b1 TO v_a2b2 
  	/INDEX=a(2) b(2).

  caseid      a     b    newvar
   
  001         1     1       .00
  001         1     2       .05 
  001         2     1      5.00
  001         2     2      3.00

• The command restructures the data file and creates two indices, A and B.