SPSS® 12.0 Command Syntax Reference

SPCHART 1517
axis. Table 6 is an example of this method of data organization. The data are the same as
in Table 5.
Table 5 Each case is a unit for c and u charts
ID Subgroup Count
1 January 0
2 January 2
3 January 0
4 January 0
5 February 5
6 February 1
7 February 0
8 February 0
... ... ...
Table 6 Each case is a sample for c and u charts
Subgroup Relapses N
JANUARY 1 4
FEBRUARY 3 4
... ... ...
Variable Specification
If data are organized as in Table 5, the variable specification on C and U subcommands is
VAR BY VAR
The variable specified before keyword BY contains the number of defects in each unit (for
example, COUNT in Table 5). It must be numeric. The variable specified after keyword BY is
the subgroup identifier (for example, SUBGROUP in Table 5). It can be any type of variable.
The chart is sorted by values of the subgroup identifier.
If data are organized as shown in Table 6, the variable specification on C and U subcommands
is
COUNT(VAR) N({VAR}) [BY VAR]
{VAL}
The specification is the same as that for p and np charts.
STATISTICS Subcommand
Any keyword may be specified in any place in the subcommand, but for a conceptual clarity
the keywords are organized as follows: the Process Capability Indices, the Process Performance
Indices, and the Measure(s) for Assessing Normality.
• This subcommand is silently ignored if the chart is not one of XR, XS, IR, and I.