Saving Summary Statistics
See SHWBOXA in the SAS/QC Sample Library
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In this example, the
BOXCHART 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 and create a summary
data set named TURBHIST:
title 'Summary Data Set for Power Output';
proc shewhart data=turbine;
boxchart kwatts*day / outhistory = turbhist
nochart;
run;
The OUTHISTORY= option names the output data set, and
the NOCHART option suppresses the display of the
chart, which would be identical to the chart in Figure 32.2.
Figure 32.6 contains a listing of TURBHIST.
Summary Data Set for Power Output |
day |
kwattsL |
kwatts1 |
kwattsX |
kwattsM |
kwatts3 |
kwattsH |
kwattsR |
kwattsN |
04JUL |
3180 |
3340.0 |
3487.40 |
3490.0 |
3610.0 |
4050 |
870 |
20 |
05JUL |
3179 |
3333.5 |
3471.65 |
3419.5 |
3605.0 |
3849 |
670 |
20 |
06JUL |
3304 |
3376.0 |
3488.30 |
3456.5 |
3604.5 |
3781 |
477 |
20 |
07JUL |
3045 |
3390.5 |
3434.20 |
3447.0 |
3550.0 |
3629 |
584 |
20 |
08JUL |
2968 |
3321.0 |
3475.80 |
3487.0 |
3611.5 |
3916 |
948 |
20 |
09JUL |
3047 |
3425.5 |
3518.10 |
3576.0 |
3615.0 |
3881 |
834 |
20 |
10JUL |
3002 |
3368.5 |
3492.65 |
3495.5 |
3621.5 |
3787 |
785 |
20 |
11JUL |
3196 |
3346.0 |
3496.40 |
3473.5 |
3592.5 |
3994 |
798 |
20 |
12JUL |
3115 |
3188.5 |
3398.50 |
3426.0 |
3568.5 |
3731 |
616 |
20 |
13JUL |
3263 |
3340.0 |
3456.05 |
3444.0 |
3505.5 |
4040 |
777 |
20 |
14JUL |
3215 |
3336.0 |
3493.60 |
3441.5 |
3616.0 |
3872 |
657 |
20 |
15JUL |
3182 |
3409.5 |
3563.30 |
3561.0 |
3719.5 |
3850 |
668 |
20 |
16JUL |
3212 |
3378.0 |
3519.05 |
3515.0 |
3682.5 |
3769 |
557 |
20 |
17JUL |
3077 |
3329.0 |
3474.20 |
3501.5 |
3599.5 |
3812 |
735 |
20 |
18JUL |
3061 |
3315.5 |
3443.60 |
3435.0 |
3614.5 |
3815 |
754 |
20 |
19JUL |
3288 |
3426.5 |
3586.35 |
3546.0 |
3762.5 |
3877 |
589 |
20 |
20JUL |
3114 |
3373.0 |
3486.45 |
3474.5 |
3635.5 |
3928 |
814 |
20 |
21JUL |
3167 |
3400.5 |
3492.90 |
3488.0 |
3582.5 |
3801 |
634 |
20 |
22JUL |
3056 |
3322.0 |
3432.80 |
3460.0 |
3561.0 |
3800 |
744 |
20 |
23JUL |
3145 |
3308.5 |
3496.90 |
3495.0 |
3652.0 |
3917 |
772 |
20 |
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Figure 32.6: The Summary Data Set TURBHIST
There are nine variables in the data set TURBHIST.
- DAY is the subgroup variable.
- KWATTSL contains the subgroup minimums.
- KWATTS1 contains the first quartiles for each subgroup.
- KWATTSX contains the subgroup means.
- KWATTSM contains the subgroup medians.
- KWATTS3 contains the third quartiles for each subgroup.
- KWATTSH contains the subgroup maximums.
- KWATTSR contains the subgroup ranges.
- KWATTSN contains the subgroup sample sizes.
Note that the summary statistic variables are named
by adding the suffix characters
L, 1, X, M,
3, H, R, and N to the
process KWATTS
specified in the BOXCHART statement.
In other words, the variable naming convention for OUTHISTORY= data
sets is the same as that for HISTORY= data sets.
If you specify the STDDEVIATIONS option,
the OUTHISTORY= data set includes a subgroup standard deviation
variable, rather than a subgroup range variable, as demonstrated by
the following statements:
title 'Summary Data Set for Power Output';
proc shewhart data=turbine;
boxchart kwatts*day / outhistory = turbhst2
stddeviations
nochart;
run;
Figure 32.7 contains a listing of TURBHST2.
The variable KWATTSS contains the subgroup
standard deviations.
The STDDEVIATIONS option is recommended when
the subgroup sample sizes are greater than 10, and it is
also recommended when you use the NOLIMITS option to create
standard side-by-side box-and-whisker plots.
For more information, see "OUTHISTORY= Data Set" .
Summary Data Set for Power Output |
day |
kwattsL |
kwatts1 |
kwattsX |
kwattsM |
kwatts3 |
kwattsH |
kwattsS |
kwattsN |
04JUL |
3180 |
3340.0 |
3487.40 |
3490.0 |
3610.0 |
4050 |
220.260 |
20 |
05JUL |
3179 |
3333.5 |
3471.65 |
3419.5 |
3605.0 |
3849 |
210.427 |
20 |
06JUL |
3304 |
3376.0 |
3488.30 |
3456.5 |
3604.5 |
3781 |
147.025 |
20 |
07JUL |
3045 |
3390.5 |
3434.20 |
3447.0 |
3550.0 |
3629 |
157.637 |
20 |
08JUL |
2968 |
3321.0 |
3475.80 |
3487.0 |
3611.5 |
3916 |
258.949 |
20 |
09JUL |
3047 |
3425.5 |
3518.10 |
3576.0 |
3615.0 |
3881 |
211.566 |
20 |
10JUL |
3002 |
3368.5 |
3492.65 |
3495.5 |
3621.5 |
3787 |
193.779 |
20 |
11JUL |
3196 |
3346.0 |
3496.40 |
3473.5 |
3592.5 |
3994 |
212.024 |
20 |
12JUL |
3115 |
3188.5 |
3398.50 |
3426.0 |
3568.5 |
3731 |
199.201 |
20 |
13JUL |
3263 |
3340.0 |
3456.05 |
3444.0 |
3505.5 |
4040 |
173.455 |
20 |
14JUL |
3215 |
3336.0 |
3493.60 |
3441.5 |
3616.0 |
3872 |
187.465 |
20 |
15JUL |
3182 |
3409.5 |
3563.30 |
3561.0 |
3719.5 |
3850 |
205.472 |
20 |
16JUL |
3212 |
3378.0 |
3519.05 |
3515.0 |
3682.5 |
3769 |
173.676 |
20 |
17JUL |
3077 |
3329.0 |
3474.20 |
3501.5 |
3599.5 |
3812 |
200.576 |
20 |
18JUL |
3061 |
3315.5 |
3443.60 |
3435.0 |
3614.5 |
3815 |
222.084 |
20 |
19JUL |
3288 |
3426.5 |
3586.35 |
3546.0 |
3762.5 |
3877 |
185.724 |
20 |
20JUL |
3114 |
3373.0 |
3486.45 |
3474.5 |
3635.5 |
3928 |
223.474 |
20 |
21JUL |
3167 |
3400.5 |
3492.90 |
3488.0 |
3582.5 |
3801 |
145.267 |
20 |
22JUL |
3056 |
3322.0 |
3432.80 |
3460.0 |
3561.0 |
3800 |
190.994 |
20 |
23JUL |
3145 |
3308.5 |
3496.90 |
3495.0 |
3652.0 |
3917 |
208.858 |
20 |
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Figure 32.7: The Summary Data Set TURBHST2
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.