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QQPLOT Statement |

**QQPLOT**<*variables*> < /*options*>;

You can specify the keyword QQ as an alias for QQPLOT, and you can use any number of QQPLOT statements in the CAPABILITY procedure. The components of the QQPLOT statement are described as follows.*variables*- are the process variables for which to create Q-Q plots.
If you specify a VAR statement, the
*variables*must also be listed in the VAR statement. Otherwise, the*variables*can be any numeric variables in the input data set. If you do not specify a list of*variables*, then by default the procedure creates a Q-Q plot for each variable listed in the VAR statement, or for each numeric variable in the DATA= data set if you do not specify a VAR statement. For example, each of the following QQPLOT statements produces two Q-Q plots, one for LENGTH and one for WIDTH:proc capability data=measures; var length width; qqplot; run; proc capability data=measures; qqplot length width; run;

*options*- specify the theoretical distribution for the plot or
add features to the plot. If you specify more than one
variable, the
*options*apply equally to each variable. Specify all*options*after the slash (/) in the QQPLOT statement. You can specify only one*option*naming the distribution in each QQPLOT statement, but you can specify any number of other*options*. The distributions available are the beta, exponential, gamma, lognormal, normal, two-parameter Weibull, and three-parameter Weibull. By default, the procedure produces a plot for the normal distribution.

In the following example, the NORMAL option requests a normal Q-Q plot for each variable. The MU= and SIGMA=*normal-options*request a distribution reference line with intercept 10 and slope 0.3 for each plot, corresponding to a normal distribution with mean and standard deviation .The SQUARE option displays the plot in a square frame, and the CTEXT= option specifies the text color.proc capability data=measures; qqplot length1 length2 / normal(mu=10 sigma=0.3) square ctext=blue; run;

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