Note: See Reading Subgroup Summary Data in the SAS/QC Sample Library.
You can use output data sets from a number of SAS procedures as input data sets for the SHEWHART procedure. In this example,
the MEANS procedure is used to create a data set containing subgroup summary statistics, which can be read by the SHEWHART
procedure as a HISTORY= data set. The following statements create an output data set named Oilsummeans
, which contains subgroup means, standard deviations, and sample sizes for the variable KWatts
in the data set Turbine
(see Creating Charts for Means and Standard Deviations from Raw Data):
proc means data=Turbine noprint; var KWatts; by Day; output out=Oilsummeans mean=means std=stds n=sizes; run;
A listing of Oilsummeans
is shown in Output 17.42.1.
Output 17.42.1: The Data Set Oilsummeans
Summary Statistics for Power Output Data |
Day | _TYPE_ | _FREQ_ | means | stds | sizes |
---|---|---|---|---|---|
04JUL | 0 | 20 | 3487.40 | 220.260 | 20 |
05JUL | 0 | 20 | 3471.65 | 210.427 | 20 |
06JUL | 0 | 20 | 3488.30 | 147.025 | 20 |
07JUL | 0 | 20 | 3434.20 | 157.637 | 20 |
08JUL | 0 | 20 | 3475.80 | 258.949 | 20 |
09JUL | 0 | 20 | 3518.10 | 211.566 | 20 |
10JUL | 0 | 20 | 3492.65 | 193.779 | 20 |
11JUL | 0 | 20 | 3496.40 | 212.024 | 20 |
12JUL | 0 | 20 | 3398.50 | 199.201 | 20 |
13JUL | 0 | 20 | 3456.05 | 173.455 | 20 |
14JUL | 0 | 20 | 3493.60 | 187.465 | 20 |
15JUL | 0 | 20 | 3563.30 | 205.472 | 20 |
16JUL | 0 | 20 | 3519.05 | 173.676 | 20 |
17JUL | 0 | 20 | 3474.20 | 200.576 | 20 |
18JUL | 0 | 20 | 3443.60 | 222.084 | 20 |
19JUL | 0 | 20 | 3586.35 | 185.724 | 20 |
20JUL | 0 | 20 | 3486.45 | 223.474 | 20 |
21JUL | 0 | 20 | 3492.90 | 145.267 | 20 |
22JUL | 0 | 20 | 3432.80 | 190.994 | 20 |
23JUL | 0 | 20 | 3496.90 | 208.858 | 20 |
The variables MEANS
, STDS
, and SIZES
do not follow the naming convention required for HISTORY= data sets (see HISTORY= Data Set. The following statements temporarily rename these variables to KWattsX
, KWattsS
, and KWattsN
, respectively (the names required when the process KWatts
is specified in the XSCHART statement):
title 'Mean and Standard Deviation Charts for Power Output'; proc shewhart history=Oilsummeans (rename=(means = KWattsX stds = KWattsS sizes = KWattsN )); xschart KWatts*Day; run;
The resulting charts are identical to the charts in FigureĀ 17.115.