See ANMXLIM in the SAS/QC Sample LibraryYou can save the decision limits for an ANOM chart, together with the parameters used to compute the limits, in a SAS data set.

The following statements read measurements from the data set `LabelDeviations`

(see the section Creating ANOM Charts for Means from Response Values) and save the decision limits displayed in Figure 4.22 in a data set named `LabelLimits`

:

proc anom data=LabelDeviations; xchart Deviation*Position / outlimits=LabelLimits nochart; run;

The OUTLIMITS= option names the data set containing the decision limits, and the NOCHART option suppresses the display of
the chart. The data set `LabelLimits`

is listed in Figure 4.26.

Figure 4.26: The Data Set LabelLimits Containing Decision Limit Information

Decision Limits for Labler Position Deviations |

_VAR_ | _GROUP_ | _TYPE_ | _LIMITN_ | _ALPHA_ | _LDLX_ | _MEAN_ | _UDLX_ | _MSE_ | _DFE_ | _LIMITK_ |
---|---|---|---|---|---|---|---|---|---|---|

Deviation | Position | ESTIMATE | 10 | 0.05 | -.009875811 | .009996667 | 0.029869 | .000643787 | 54 | 6 |

The data set `LabelLimits`

contains one observation with the limits for *response* `Deviation`

. The values of `_LDLX_`

and `_UDLX_`

are the lower and upper decision limits for the means, and the value of `_MEAN_`

is the weighted average of the group means, which is represented by the central line.

The values of `_MEAN_`

, `_MSE_`

, `_DFE_`

, `_LIMITN_`

, `_LIMITK_`

, and `_ALPHA_`

are the parameters used to compute the decision limits as described in the section Constructing ANOM Charts for Means. The value of `_MSE_`

is the mean square error, and the value of `_DFE_`

is the associated degrees of freedom. The value of `_LIMITN_`

is the nominal sample size (n) associated with the decision limits, the value of `_LIMITK_`

is the number of groups (k), and the value of `_ALPHA_`

is the value of the significance level (). The variables `_VAR_`

and `_GROUP_`

are bookkeeping variables that save the *response* and *group-variable*. The variable `_TYPE_`

is a bookkeeping variable that indicates whether the values of `_MEAN_`

and `_MSE_`

are estimates computed from the data or standard (known) values specified with procedure options. In most applications, the
value of `_TYPE_`

will be 'ESTIMATE.'

See ANMXTAB in the SAS/QC Sample LibraryYou can create an output data set containing both decision limits and group summary statistics with the OUTTABLE= option, as illustrated by the following statements:

proc anom data=LabelDeviations; xchart Deviation*Position / outtable=LabelTab nochart; run;

The data set `LabelTab`

is listed in Figure 4.27.

Figure 4.27: The Data Set `LabelTab`

Summary Statistics and Decision Limits |

_VAR_ | Position | _ALPHA_ | _LIMITN_ | _SUBN_ | _LDLX_ | _SUBX_ | _MEAN_ | _UDLX_ | _EXLIM_ |
---|---|---|---|---|---|---|---|---|---|

Deviation | 1 | 0.05 | 10 | 10 | -.009875811 | -0.02234 | .009996667 | 0.029869 | LOWER |

Deviation | 2 | 0.05 | 10 | 10 | -.009875811 | 0.01625 | .009996667 | 0.029869 | |

Deviation | 3 | 0.05 | 10 | 10 | -.009875811 | 0.00604 | .009996667 | 0.029869 | |

Deviation | 4 | 0.05 | 10 | 10 | -.009875811 | 0.06473 | .009996667 | 0.029869 | UPPER |

Deviation | 5 | 0.05 | 10 | 10 | -.009875811 | 0.00813 | .009996667 | 0.029869 | |

Deviation | 6 | 0.05 | 10 | 10 | -.009875811 | -0.01283 | .009996667 | 0.029869 | LOWER |

This data set contains one observation for each group sample. The variables `_SUBX_`

and `_SUBN_`

contain the group means and sample sizes. The variables `_LDLX_`

and `_UDLX_`

contain the lower and upper decision limits, and the variable `_MEAN_`

contains the central line. The variables `_VAR_`

and `Position`

contain the *response* name and values of the *group-variable*, respectively. For more information, see the section OUTTABLE= Data Set.

An OUTTABLE= data set can be read later as a TABLE= data set. For example, the following statements read `LabelTab`

and display an ANOM chart (not shown here) identical to the chart in Figure 4.22:

title 'Analysis of Label Deviations'; proc anom table=LabelTab; xchart Deviation*Position; label _SUBX_ = 'Mean Deviation from Center (mm)'; run;

Because the ANOM procedure simply displays the information in a TABLE= data set, you can use TABLE= data sets to create specialized ANOM charts.

For more information, see the section TABLE= Data Set.