Date:         Wed, 20 Feb 2002 14:20:46 +0100
Reply-To:     Dave Sorensen <Dave.Sorensen@JUR.KU.DK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Dave Sorensen <Dave.Sorensen@JUR.KU.DK>
Subject:      SV: coding a cumulative variable in univariate data
Content-Type: text/plain; charset="iso-8859-1"

Dear Jim,

Thanks for the suggestion.  But the datastep's log file says: Variable
First.Subj is uninitialized.  The result was that all subjects =1 on the new
variable (regardless of whether they had ever experienced the event).

Also, was I clear that the new variable should not =1 UNTIL the event has
occurred, but should then remain=1 thereafter.

Dave



-----Oprindelig meddelelse-----
Fra: Jim Groeneveld [mailto:J.Groeneveld@ITGroups.com]
Sendt: Wednesday, February 20, 2002 12:54 PM
Til: 'Dave Sorensen'; SAS-L@LISTSERV.UGA.EDU
Emne: RE: coding a cumulative variable in univariate data


Dear Dave,

Try the following program:

DATA basic;
  INPUT Subj Time X;
  DATALINES;
  1 1 0
  1 2 3
  1 3 0
  2 1 0
  2 2 0
  2 3 1
  ;
RUN;

PROC SORT DATA=basic; BY Subj Time; RUN;

DATA cumul;
  SET basic; BY Subj Time;
  RETAIN EverX;
  IF (First.Subj) THEN EverX = 0;
  IF (X GT 0) THEN EverX = 1;
RUN;

PROC PRINT DATA=cumul; RUN;

Regards - Jim.
--
Y. (Jim) Groeneveld, MSc      IMRO TRAMARKO       tel. +31 412 407 070
senior statistician,          P.O. Box 1          fax. +31 412 407 080
senior data manager           5350 AA BERGHEM     IMRO TRAMARKO: a CRO
J.Groeneveld@ITGroups.com     the Netherlands     in clinical research

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> -----Original Message-----
> From: Dave Sorensen [SMTP:Dave.Sorensen@JUR.KU.DK]
> Sent: Wednesday, February 20, 2002 12:27 PM
> To:   SAS-L@LISTSERV.UGA.EDU
> Subject:      coding a cumulative variable in univariate data
>
> Dear SAS-L,
>
> I have a univariate data set where each subject-wave is a separate
> observation.
>
> I have a variable called X.  I would like to create a dummy variable
> called
> EVERx which=1 if X is, or has ever been greater than 0.  The result should
> look like this.
>
> SUBJ    TIME            X               EVERx
> 1       1               0               0
> 1       2               3               1
> 1       3               0               1
> 2       1               0               0
> 2       2               0               0
> 2       3               1               1
>
> Is there a simple way to code this with the data in univariate format, or
> do
> I need to transform the data to multivariate format, code EVERx wave to
> wave, and then transform it back to univariate format?
>
> Thanks in advance!
>
> Dave Sorensen