XSCHART Statement: SHEWHART Procedure

Axis Labels

You can specify axis labels by assigning labels to particular variables in the input data set, as summarized in the following table:

Axis

Input Data Set

Variable

Horizontal

all

subgroup-variable

Vertical ($\bar{X}$ chart)

DATA=

process

Vertical ($\bar{X}$ chart)

HISTORY=

subgroup mean variable

Vertical ($\bar{X}$ chart)

TABLE=

_SUBX_

You can specify distinct labels for the vertical axes of the $\bar{X}$ and s charts by breaking the vertical axis into two parts with a split character. Specify the split character with the SPLIT= option. The first part labels the vertical axis of the $\bar{X}$ chart, and the second part labels the vertical axis of the s chart.

For example, the following sets of statements specify the label Avg Power Output for the vertical axis of the $\bar{X}$ chart and the label Std Deviation for the vertical axis of the s chart:

proc shewhart data=Turbine;
   xschart KWatts*Day / split = '/' ;
   label KWatts = 'Avg Power Output/Std Deviation';
run;

proc shewhart history=Turbhist;
   xschart KWatts*Day / split = '/' ;
   label KWattsX = 'Avg Power Output/Std Deviation';
run;

proc shewhart table=Turbtab;
   xschart KWatts*Day / split = '/' ;
   label _SUBX_ = 'Avg Power Output/Std Deviation';
run;

In this example, the label assignments are in effect only for the duration of the procedure step, and they temporarily override any permanent labels associated with the variables.