Saving Summary Statistics :: SAS/QC(R) 12.1 User's Guide

Saving Summary Statistics

See SHWXR1 in the SAS/QC Sample LibraryIn this example, the XRCHART 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 Wafers and create a summary data set named Waferhist:

proc shewhart data=Wafers;
   xrchart Diameter*Batch / outhistory = Waferhist
                            nochart;
run;

The OUTHISTORY= option names the output data set, and the NOCHART option suppresses the display of charts. Figure 17.108 contains a partial listing of Waferhist.

Figure 17.108: Partial Listing of the Summary Data Set Waferhist

Summary Data Set for Wafer Diameters

Batch	DiameterX	DiameterR	DiameterN
1	34.992	0.02	5
2	34.994	0.03	5
3	34.998	0.01	5
4	34.998	0.02	5
5	34.992	0.02	5

There are four variables in the data set Waferhist:

Batch contains the subgroup index.
DiameterX contains the subgroup means.
DiameterR contains the subgroup ranges.
DiameterN contains the subgroup sample sizes.

Note that the summary statistic variables are named by adding the suffix characters X, R, and N to the process Diameter specified in the XRCHART 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.

XRCHART Statement: SHEWHART Procedure

Saving Summary Statistics