The basic syntax for the XSCHART statement is as follows:
- XSCHART process*subgroup-variable ;
The general form of this syntax is as follows:
- XSCHART (processes)*subgroup-variable
<(block-variables ) >
- < =symbol-variable | ='character' >
< / options >;
You can use any number of XSCHART statements
in the SHEWHART procedure.
The components of the XSCHART statement are described as follows.
identify one or more processes to be analyzed.
The specification of process depends on
the input data set specified in the PROC SHEWHART
A process is required. If more than one process is
specified, enclose the list in parentheses. For example, the
following statements request distinct and s charts for
WEIGHT, LENGTH, and WIDTH:
proc shewhart data=measures;
xschart (weight length width)*day;
is the variable that identifies subgroups in the data.
The subgroup-variable is required.
In the preceding XSCHART statement, DAY is the subgroup variable.
For details, see "Subgroup Variables" .
are optional variables that group the data
into blocks of consecutive subgroups. The blocks are
labeled in a legend, and each block-variable provides
one level of labels in the legend.
See "Displaying Stratification in Blocks of Observations" for an example.
is an optional variable whose levels (unique values) determine the
symbol marker or character used to plot the means and standard
- If you produce a chart on a line printer,
an `A' is displayed for the points corresponding to the first level of
the symbol-variable, a `B' is displayed for the points
corresponding to the second level, and
- If you produce a chart on a graphics device,
distinct symbol markers are displayed for points
corresponding to the various levels of the symbol-variable.
You can specify the symbol markers with SYMBOLn statements.
See "Displaying Stratification in Levels of a Classification Variable" for an example.
specifies a plotting character for charts produced on
For example, the following statements create and
s charts using an asterisk (*) to plot the points:
proc shewhart data=values;
- enhance the appearance of the charts, request additional analyses,
save results in data sets, and so on. The "Summary of
Options" section, which follows, lists all options by function.
Chapter 46, "Dictionary of Options," describes each
option in detail.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.