The basic syntax for the MCHART statement is as follows:
- MCHART process*subgroup-variable ;
The general form of this syntax is as follows:
- MCHART (processes)*subgroup-variable
<(block-variables ) >
- < =symbol-variable | ='character' >
< / options >;
You can use any number of MCHART statements in the SHEWHART procedure.
The components of the MCHART 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 you specify more than one process, enclose the list in parentheses.
For example, the following statements request distinct median charts
for WEIGHT, LENGTH, and WIDTH:
proc shewhart data=measures;
mchart (weight length width)*day;
is the variable that identifies subgroups in the data. The
subgroup-variable is required. In the preceding MCHART
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 medians.
- 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 median chart 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.