Saving Summary Statistics

[See SHWXS1 in the SAS/QC Sample Library]In this example, the XSCHART statement is used to create a summary data set that can be read later by the SHEWHART procedure (as in the preceding example). The following statements read measurements from the data set Turbine (see Creating Charts for Means and Standard Deviations from Raw Data) and create a summary data set named Turbhist:

proc shewhart data=Turbine;
   xschart KWatts*Day / outhistory = Turbhist
                        nochart;
run;

The OUTHISTORY= option names the output data set, and the NOCHART option suppresses the display of the charts, which would be identical to those in Figure 13.40.6. Options such as OUTHISTORY= and NOCHART are specified after the slash (/) in the XSCHART statement. A complete list of options is presented in the section Syntax.

Figure 13.40.9 contains a partial listing of Turbhist.

There are four variables in the data set Turbhist.

• Day contains the subgroup index.

• KWattsX contains the subgroup means.

• KWattsS contains the subgroup standard deviations.

• KWattsN contains the subgroup sample sizes.

Note that the summary statistic variables are named by adding the suffix characters X, S, and N to the process KWatts specified in the XSCHART statement. In other words, the variable naming convention for OUTHISTORY= data sets is the same as that for HISTORY= data sets.

For more information, see OUTHISTORY= Data Set.