/PCOMPUTE&postcompute=EXPR(expression)/PPROPERTIES&postcompute... [LABEL=string] [FORMAT=[summary format]...] [HIDESOURCECATS={NO|YES}
Computed categories, also called postcomputes, are
categories created using arithmetic on categories obtained from the
data. The PCOMPUTE subcommand creates a postcompute, which may
then be used on CATEGORIES within an explicit category list
(see CTABLES Explicit Category List). Optionally,
PPROPERTIES refines how a postcompute is displayed. The
following sections provide the details.