Lognormal Q-Q Plots for Nonnormal Data

 /****************************************************************/
 /*          S A S   S A M P L E   L I B R A R Y                 */
 /*                                                              */
 /*    NAME: CAPQQPL3                                            */
 /*   TITLE: Lognormal Q-Q Plots for Nonnormal Data              */
 /* PRODUCT: QC                                                  */
 /*  SYSTEM: ALL                                                 */
 /*    KEYS: Capability Analysis, Quantile-Quantile Plots,       */
 /*   PROCS: CAPABILITY                                          */
 /*    DATA:                                                     */
 /*                                                              */
 /*     REF: SAS/QC Software:  Examples                          */
 /*    MISC: Differences between graphics devices may result in  */
 /*          output that varies from that shown in the documen-  */
 /*          tation.  Check the SAS log if the graphical output  */
 /*          is not created.                                     */
 /*                                                              */
 /****************************************************************/

options ps=60 ls=80;

data plates;
   label gap='Plate Gap in cm';
   input gap @@;
   cards;
0.746  0.357  0.376  0.327  0.485
1.741  0.241  0.777  0.768  0.409
0.252  0.512  0.534  1.656  0.742
0.378  0.714  1.121  0.597  0.231
0.541  0.805  0.682  0.418  0.506
0.501  0.247  0.922  0.880  0.344
0.519  1.302  0.275  0.601  0.388
0.450  0.845  0.319  0.486  0.529
1.547  0.690  0.676  0.314  0.736
0.643  0.483  0.352  0.636  1.080
;

symbol1 c=white v=star h=1.5 ;    /* Q-Q Points */

title 'Lognormal Q-Q Plot of Plate Gaps';

proc capability data=plates noprint;
   var gap;
   specs lsl=0.3 clsl=yellow llsl=1
         usl=0.8 cusl=yellow lusl=20;
   qqplot /
      cframe=gray
      legend=legend1
      lognormal(sigma=0.3 0.5 0.7)
      square;
   legend1 cframe=gray cborder=black;
run;

goptions reset=all;