preserve.
set printback=on.

* SIMPLE AND COMPLEX RANDOM ASSIGNMENT IN EXPERIMENTAL DESIGNS
  Valentim R. Alferes, University of Coimbra (Portugal), 2009.

* CC2.sps - Complete counterbalacing (2 treatments/2 sequences).

set printback=off.
set ovars labels onumbers values tvars labels tnumbers values.
set errors=none.
data list free /Sequence(a10).
begin data
AB BA
end data.

* Enter number of units per sequence. 
compute units= 8.

loop cases=1 to units.
xsave outfile=outf1/keep=Sequence.
end loop.
execute.
get file=outf1.
set seed random.
compute random=uniform(1).
sort cases by random(a).
rank variables=random(a)/print=no.
compute Unit=rrandom.
formats all(f8.0).
oms/select tables/if commands=["summarize"]
 subtypes=["case processing summary"]/destination viewer=no.
oms/select tables/if commands=["crosstabs"]
 subtypes=["case processing summary"]/destination viewer=no.
summarize/tables=unit sequence/format=validlist nocasenum nototal
 /title='Complete Counterbalancing \n Sorted by Unit'/cells=none.
sort cases by sequence(a) unit(a).
summarize/tables= unit sequence/format=validlist nocasenum nototal
 /title='Complete Counterbalancing \n Sorted by Sequence'/cells=none.
summarize/tables=unit  by sequence/format=nolist total
 /title='Number of Units per Sequence'/cells=count npct.
restore.