Date:         Sat, 7 Jul 2007 11:25:28 -0400
Reply-To:     Muthia Kachirayan <muthia.kachirayan@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Muthia Kachirayan <muthia.kachirayan@GMAIL.COM>
Subject:      Re: How to assign the 2nd obs value to the 1st obs
Comments: To: Sophia Tong <sophiDT@hotmail.com>
In-Reply-To:  <200707062257.l66KCUYS003332@mailgw.cc.uga.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Sophia,

The lag-function goes by ignoring group-boundaries(PR-PP). You can save it
to say, PREV and use it in the next observation. Here is the code as I
understand your problem.

data have;
 input pr pp pe ;
 cards;
26117       12644       78765
26117       12644       78766
26117       12644       78767
26117       12644       79398
26117       12644       80601
26117       12644       81343
26117       12644       81503
26117       12644       83429
32640       15436      107309
32640       15436      114404
32640       15436      163072
32640       15436      166924
32640       15436       94725
32640       15436       94726
32640       15436       94727
32640       15436       94728
;
run;

proc sort data = have;
by pr pp;
run;

data want;
set have;
by pr pp;
retain prev;
if first.pp then pe_diff = 1;
else do;
    if (pe - prev) = 1 then pe_diff = 1;
    else pe_diff = 0;
end;
prev = pe;
run;

proc print data = want;
run;

Muthia Kachirayan


On 7/6/07, Sophia Tong <sophiDT@hotmail.com> wrote:
>
> Dear list,
>
> I am trying to determine whether a call is a real counseling call or
> random
> incoming call by looking at the PE numbers.  If under the same PR-PP, PE
> come as a sequential numbers then that set of sequential numbers consider
> as
> a set of counseling calls.
>
> What I did is let PE2=lag(PE), then PE_DIFF=PE-PE2, if PE_DIFF=1 then that
> call identified as a conseling call. As you see below, the first obs with
> PE_DIFF=-264, this one should be identified as a real call. Another one
> where PE_DIFF=-72199, that one also should be identified as a real call.
>
> My question is how to assign 1s to IND_PEDIFF after SAS see the first 1s
> in
> PE_DIFF?
> Mine way of flagging  in IND_PEDIFF does not cover all the cases.  Please
> help.
>
> Thanks in advance.
>
> Sophia
>                                          The SAS System           08:03
> Friday, July 6, 2007  30
>
>                                                                      IND_
>              PR           PP           PE        PE2     PE_DIFF    PEDIFF
>   CALLS
>
>               26117       12644       78765     79029       -264       1
>      1
>               26117       12644       78766     78765          1       1
>      2
>               26117       12644       78767     78766          1       1
>      3
>               26117       12644       79398     78767        631       0
>      4
>               26117       12644       80601     79398       1203       0
>      5
>               26117       12644       81343     80601        742       0
>      6
>               26117       12644       81503     81343        160       0
>      7
>               26117       12644       83429     81503       1926       0
>      8
>               32640       15436      107309     94633      12676       1
>      1
>               32640       15436      114404    107309       7095       0
>      2
>               32640       15436      163072    114404      48668       0
>      3
>               32640       15436      166924    163072       3852       0
>      4
>               32640       15436       94725    166924     -72199       0
>      5
>               32640       15436       94726     94725          1       1
>      6
>               32640       15436       94727     94726          1       1
>      7
>               32640       15436       94728     94727          1       1
>      8
>