Rare Events Chart for Days between Infections

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/*          S A S   S A M P L E   L I B R A R Y                 */
/*                                                              */
/*    NAME: RAREGS                                              */
/*   TITLE: Rare Events Chart for Days between Infections       */
/* PRODUCT: QC                                                  */
/*  SYSTEM: ALL                                                 */
/*    KEYS:                                                     */
/*   PROCS: RAREEVENTS                                          */
/*    DATA:                                                     */
/*                                                              */
/* SUPPORT: saswgr                                              */
/*     REF: PROC RAREEVENTS, Getting Started                    */
/*                                                              */
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data Infections;
   input InfectionDate mmddyy10.;
   InfectionNumber = _n_;
   DaysBetween = InfectionDate - lag(InfectionDate);
   format InfectionDate  mmddyy10.;
datalines;
04/17/1995
04/17/1995
04/17/1995
04/19/1995
04/20/1995
05/03/1995
05/05/1995
05/05/1995
05/06/1995
05/07/1995
05/08/1995
05/09/1995
05/09/1995
05/10/1995
05/11/1995
05/27/1995
05/27/1995
05/28/1995
05/29/1995
05/31/1995
06/10/1995
06/11/1995
06/12/1995
06/14/1995
06/16/1995
06/16/1995
06/18/1995
06/21/1995
06/21/1995
;

ods graphics on;
proc rareevents data=Infections;
   compare DaysBetween;
   chart DaysBetween * InfectionNumber;
   label DaysBetween = 'Days between Infections';
run;