The basic syntax for the BOXCHART statement is as follows:
- BOXCHART process*subgroup-variable ;
The general form of this syntax is as follows:
- BOXCHART (processes)*subgroup-variable
<(block-variables ) >
- < =symbol-variable | ='character' >
< / options >;
You can use any number of BOXCHART statements in the SHEWHART
procedure. The components of the BOXCHART statement are described
identify one or more processes to be analyzed.
The specification of process depends on
the input data set specified in the PROC SHEWHART statement.
- If raw data are read from a DATA= data set, process
must be the name of the variable containing the raw measurements.
For an example,
see "Creating Box Charts from Raw Data" .
- If summary data are read from a HISTORY= data set,
process must be the common prefix of the
summary variables in the HISTORY= data set.
For an example, see "Creating Box Charts from Subgroup Summary Data" .
- If summary data and control limits are read from a TABLE= data
set, process must be the value of the variable _VAR_ in
the TABLE= data set.
For an example, see "Saving Control Limits" .
A process is required. If you specify more than one
process, enclose the list in parentheses. For example, the
following statements request distinct box charts for WEIGHT, LENGTH,
proc shewhart data=summary;
boxchart (weight length width)*day;
is the variable that identifies subgroups in the data. The
subgroup-variable is required. In the preceding BOXCHART
statement, DAY is the subgroup variable.
For details, see "Subgroup Variables" .
are optional variables that group the data into blocks of
consecutive subgroups. These 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.
- 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 so on.
- 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 line printers.
For example, the following statements create a box chart
using an asterisk (*) to plot the means:
proc shewhart data=values;
- enhance the appearance of the box chart, 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.