The basic syntax for the EWMACHART statement is as follows:
- EWMACHART process*subgroup-variable / WEIGHT=value < options > ;
- The general form of this syntax is as follows:
- EWMACHART (processes)*subgroup-variable <( block-variables ) >
- < =symbol-variable |
='character' > / WEIGHT=value < options >;
- Note that the WEIGHT= option is required unless
its value is read from a LIMITS= data set.
You can use any number of EWMACHART statements in the
The components of the EWMACHART 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 MACONTROL
A process is required. If more than one process is
specified, enclose the list in parentheses.
For example, the
following statements request distinct EWMA
charts (each using a weight parameter of 0.3)
for WEIGHT, LENGTH, and WIDTH:
proc macontrol data=measures;
ewmachart (weight length width)*day / weight=0.3;
is the variable that classifies the data into subgroups.
The subgroup-variable is required.
In the preceding EWMACHART 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 plotting character used to plot
- 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 an
using an asterisk (*) to plot the points:
proc macontrol data=values;
ewmachart length*hour='*' / weight=0.3;
- specify chart parameters, enhance the appearance of the
chart, request additional analyses, save results in data sets, and so
on. The "Summary of Options" section, which follows, lists all
options by function.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.