PROC SHEWHART: Saving Summary Statistics

Saving Summary Statistics

[See SHWMR1 in the SAS/QC Sample Library]In this example, the MRCHART 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 Detergent and create a summary data set named Dethist:

proc shewhart data=Detergent;
   mrchart Weight*Lot / outhistory = Dethist
                        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 the charts in Figure 15.45. Options such as OUTHISTORY= and NOCHART are specified after the slash (/) in the MRCHART statement. A complete list of options is presented in the section Syntax: MRCHART Statement.

Figure 15.48 contains a partial listing of Dethist.

Figure 15.48 The Summary Data Set Dethist

Summary Data Set DETHIST for Detergent Box Weights

Lot	WeightM	WeightR	WeightN
1	22.56	9.54	5
2	23.54	3.07	5
3	24.35	4.65	5
4	25.52	5.05	5
5	23.25	8.04	5

There are four variables in the data set Dethist.

Lot contains the subgroup index.
WeightM contains the subgroup medians.
WeightR contains the subgroup ranges.
WeightN contains the subgroup sample sizes.

Note that the summary statistic variables are named by adding the suffix characters M, R, and N to the process Weight specified in the MRCHART 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.

MRCHART Statement: SHEWHART Procedure

Saving Summary Statistics